4 Tertiary Protein Structure and Folds 4.1 Introduction. Which of the following amino acids is unlikely to be found in an . It is well established that protein structures are more conserved than protein sequences. Today it also symbolizes friendship, love and devotion and - especially in the round version of it - Fertility. 12. -Helices and -Sheets Supersecondary structures: the combination of - and -sections, as for example unit: two parallel strands of -sheet connected by a stretch of -helix unit: two antiparallel -helices -meander: an antiparallel sheet formed by a series of tight reverse turns connecting stretches of a polypeptide chain Greek key: a repetitive . In biochemistry, the term Greek Key refers to a kind of supersecondary structure or motif of a protein (amino-acid) sequence. This type of structure forms easily during the protein folding process. Greek Key Jewelry uses the "meander motif" which became a very important symbol in ancient Greece appearing in clothes, buildings, temples, as well as pottery. The Greek key motif has its name because the structure looks like the pattern seen on Greek urns. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features Press Copyright Contact us Creators . The word meander, in Greek, meaning to take an indirect path, derives from the twisting and turning path of the Maeander River in Asia Minor (present-day Turkey . Chapters 1 and 2 introduced alpha-helices and beta-sheets (Secondary Structure), and some common "motifs" composed of 2 or 3 of these elements (Super-secondary Structure).Tertiary structure describes the folding of the polypeptide chain to assemble the different secondary structure elements in a particular arrangement. It may not necessarily have a biological functions. c. A double-layered arrangement formed so that the polar groups face the aqueous environment, while the nonpolar regions are kept away from the aqueous environment. WikiMatrix Some simple combinations of secondary structure elements have been found to frequently occur in protein structure and are referred to as supersecondary structure or motifs. Which statement below does not describe fibrous proteins? Protein Taxonomy-The CATH Hierarchy 1. on example is the EF hand, the and! arrangement of secondary structure elements The term motif is used in two different ways in structural biology. These proteins constitute the bulk of the human eye lens, packed at very high concentrations in a compact, globular, short-range order, generating transparency. This pattern became particularly important to the classical Greeks and then Romans. Bovine Trypsin Inhibitor Snake Venom Erabutoxin Greek Key Motif Motif. The Greek key is a very common structural motif in proteins. Greek key, also referred to as meander, is in its most basic form a linear pattern. Mixed supersecondary structures [ edit] The Greek Key pattern, also known as a meander pattern, is most often used as a linear pattern. A structural motif does not have to be associated with a sequence motif; . For instance, common secondary structures are often grouped together to form a motifs called super-secondary structure (SSS). It consists of three antiparallel strands connected by hairpins, while the fourth is adjacent to the first and linked to the third by a longer loop. The Greek key motifs are the topological signature of many beta-barrels and a majority of beta-sandwich structures. An example is the so-called zinc finger motif, CXX(XX)CXXXXXXXXXXXXHXXXH, which is found in a widely varying family of DNA-binding proteins (Figure 1-49). The pattern can be found in a variety of forms. This motif has no known function. RASMOL - gcrysb.pdb The jellyroll topology Example of a protein with jellyroll topology: Carbohydrate-Binding Module Family 28 from Clostridium josui Cel5A (3ACI) Example of a b-barrel (red fluorescent protein; 3NED) The b-helix Supersecondary structure. An updated survey of these structures integrates many early observations and newly emerging patterns and provides a better understanding of the unique role of Greek keys in protein structures. A complex protein has three subunits. How this Greek key-derived dense packing of the - and - crystallins in the eye lens translates into transparency is an issue of biological functional interest. The collagen helix and the a-helix are the only types of helices in proteins. B. Globular proteins tend to be water soluble C. Globular and fibrous are examples of secondary . The Greek key motif is an evolutionarily conserved super-secondary protein structural fold that offers structural compactness and high intrinsic stability against stress. Menurut ensiklopedia, manakah yang tidak termasuk supersecondary structure (motif) dari struktur molekul protein ?? See more Zinc finger. The same can be done to a -sheet, and in this case the resulting structure would be a -barrel. Connection between helixes can vary greatly in length and the axis of helix is roughly parallel to the -strands; thereby all three elements interact to . Beta-hairpins Beta-hairpins are one of the simplest supersecondary structures and are widespread in globular proteins. In this section we will look at motifs consisting of no more than three secondary structure elements. Sort by. Larger motifs such as the Greek key will be examined in the sections on The secondary and SSS elements are combined together, with help of various types of coils, to form the tertiary structure. 2 Super-secondary structure Secondary structure elements are observed to combine in specific geometric arrangements known as motifs or super-secondary structures. Four strands hydrogen-bonded individual -st Greek keys are quite diverse in topology and hence were further classified as (4,0), (3,1), and (2,2) patterns, based on the arrangement and connectivity of strands ( 46 ). A. Horizontal and vertical lines, connected at right angles Classication /a > on example is EF. Use Nanome to learn about proteins in Virtual Reality:Website - http://bit.ly/2qssBS5Steam - https://store.steampowered.com/app/493430/Nanome/Oculus - https:. Apakah . A. the pyrrole ring B. the Greek key C. the b-meander D. the b-barrel 28. Forming Greek Key Motif Suggested folding pathway from a hairpin-like structure to the Greek key motif. The first strand (N-terminal strand) and the last strand (C- terminal strand) are adjacent to each other and hydrogen bonds exist between them. The design is made up of a long, continuous line that repeatedly folds back on itself, mimicking the ancient . strands or helices) and a turn (or loop) Helix-turn-helix DNA binding motif. The Greek Key motif symbolizes the infinite and . Greek Key and Jelly-Roll) consisting of more than 3 secondary structures will be considered along with tertiary structures and folds Why? Lecture . The Greek key is a very common structural motif in proteins. At its most basic, it is a band consisting of short horizontal and vertical lines, connected at right angles. A) Each amino acid will have either an a-amino group or an a-carboxyl B) The a-amino and a-carboxyl groups are frequently modified by C) The R groups of amino acids will vary in structure, size, electrical charge D) The central or a-carbon of the amino acid is bonded to three other group. An example is a 13-a- loop . This motif is more complex in terms of structural organization compared to -- and --hairpins, and consists of two parallel -strands connected by an -helix. Beta strands 2 and 3 fold over such that strand 2 is aligned adjacent and antiparallel to strand 1. Greek key may refer to: Greek key (art), a decorative border constructed from a continuous line, shaped into a repeated motif Greek key (protein structure), a repeated motif in the secondary structure in proteins See also [ edit] Greek keyboard Greek keyhole limpet This disambiguation page lists articles associated with the title Greek key. The Greek key design symbolizes infinity or the eternal flow of life. The Greek key motif has its name because the structure looks like the pattern seen on Greek urns. Note that a . Divide PDB structure entries into domains (using domain recognition algorithms--the domain is the fundamental unit of structure classification 2. Supersecondary structure (motif) was coined by Branden & Tooze (1991) ie. Lihat juga kunci jawaban pertanyaan berikut: Seorang anak laki-laki berusia 5 tahun dibawa oleh Ibunya ke puskesmas dengan keluhan bila senja sering terjatuh akibat tersandung oleh mainannya. Which of the following is true? The three dimensional structure of the enzyme Staphylococcus Nuclease shown in (b) in blue and red is also a Greek key motif. Examples include -hairpins, -helix hairpins, and -- motifs . A motif or fold is a recognizabl folding pattern involvin two or more elements of secondary structure d the connection(s) between them. See . Download this BIOC12H3 class note to get exam ready in less time! As a consequence of the weak affinity of Nsp9 which of the following are not an example of supersecondary structure a. pyrrole ring b. greek key c. b meander d. b barrel: A. pyrrole ring: the protein collagen a. double helical structure b. contains hydroxyproline c. contains no glycine d. is a prime example of a globular protein: b. contains hydroxyproline This is why you will often find the Greek Key design on wedding bands as a symbol of eternal love. supersecondary structures include -helix hairpins, hairpins, coiled coils, Greek key, and --, -turn-,-loop-, and Rossmann motifs. 17. Classify each domain according to a five level hierarchy: Class Architecture Topology Homologous Superfamily Sequence Family the top 3 levels of the hierarchy . A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions (Zn2+) in order to . It . A supersecondary region, often shared by proteins, that has a specific function. In ancient Greece, the Greek Key was a symbol for 'infinity' and the 'eternal flow of things'. Greek key V; -meander V; Kunci jawabannya adalah: B. -barrel. Consensus amino acid sequence and secondary structure of the leucine-rich motifs of type A and type B. X denotes any amino acid; a denotes an aliphatic amino acid. In the absence of ascorbic acid, prolyl oxidase is unable to oxidize proline residues in collagen to hydroxyproline, resulting in: scurvy. Name and describe the specific type of interaction that often stabilizes secondary structure. They are stabilized by hydrogen bonds between the carbonyl and NH groups in the peptide backbone. The design was named "meander" after the twisting and turning of the Meander river in present-day Turkey. The design is a geometric line that repeatedly folds back on itself, thus mimicking the Meander River of Asia Minor. Which of the following amino acids combinations have side chains with . discovered the so-called Greek key topology: it has been shown that this structural motif occurs in 70% of proteins. It has been traditionally defined as four -strands with ' +3,-1,-1' topology. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when read in opposite directions, base-pair to form a double helix that ends in an unpaired loop. Consider a piece of paper; if it were rolled into a tube, it would still be a piece of paper, but it would have been modified into a more complex structure. However, it has been found that similar substructures are found in proteins. The structure is also known as a hairpin or hairpin loop. Class note uploaded on Dec 3, 2012. Domains have a globular fold. Structural databases Lecture 5 Structural Bioinformatics Dr. Avraham Samson 81 -871 Four Greek key motifs arranged into two b-barrels. The meander or meandros (Greek: ), or Greek Key, is a decorative border created from a continuous line, shaped into a repeated motif, much used in Greek and Roman art. -barrel. A repetitive supersecondary structure. GREEK KEY MOTIF formed by four sequentially connected -strands adjacent to each other (geometrically aligned to each other)- Alternate strands runs in the opposite direction. In art and architecture, a meander is a decorative border constructed from a continuous line, shaped into a repeated motif. Current Matches Filter Results (56) Filter by Category: All Categories Buy & Sell (56) Arts & Collectibles . The sandwich is two layers of sheet. Large supersecondary structures can be domains. So, basically, a protein motif is a supersecondary structure consisting alpha helix and/or beta sheet and random coil. Another interesting approach to this problem is based on the analysis of the folding mechanism of proteins (5): it has been shown that the number of permissible topologies depends on the number of-strandsandonthefoldingpathway.Furthermore,anumberof regularities for -sheet motifs . The supersecondary structure refers to a specific combination of secondary structure elements, such as -- units or a helix-turn-helix motif. Super secondary structure (Motif) Secondary structures often group together to form a specific geometric arrangements known as motifs Since motifs contain more than one secondary structural element, these are referred to as super secondary structures Simple motifs can combine to form more complex motifs Recognizing motifs helps decompose complex protein structures into simpler units that can . The first refers to a particular amino-acid sequence that is characteristic of a specific biochemical function. A motif can be very simple, such as two elements of secondary structure folded against each other, and represent only a small part of a protein. The Greek key motifs are the topological signature of many -barrels and a majority of -sandwich structures. EF-hand Calcium-binding Motif The Hairpin Motif. Which one is not an example of supersecondary structure? A stereotypical Greek key -barrel accommodates five or six strands and can have 12 . The simplest motif is the formation of a "loop", known as a -turn if it is short, while an unstructured connection is termed a "coiled region". It is named for its resemblance to the Greek Key meander pattern in art. The ---motif is a mixed type of SSS (supersecondary structure) . Handedness Leucine-rich Motifs. An example that displays the secondary structures and the hairpin supersecondary structure is given in Figure . The most prevalent SSPs are typically present in superfolds such as the Rossmann-like fold, the ferredoxin-like fold and the Greek key motif, whereas the less frequent SSPs often possess split . a. This definition encompasses motifs with several different three-dimensional structures. The Greek key motif consists of four adjacent antiparallel strands and their linking loops. An updated survey of these structures integrates many early observations and newly emerging patterns and provides a better understanding of the unique role of Greek keys in protein structures. [Pg.470] Frequently recurring substructuresor folds are collectively termed supersecondary structuresor motifs. This motif has no known function. -sheets composed of multinational hydrogen-bonded individual -strands are sometimes considered a secondary or supersecondary structure. Check out our greek key motif selection for the very best in unique or custom, handmade pieces from our shops. Background: We highlight an unrecognized physiological role for the Greek key motif, an evolutionarily conserved super-secondary structural topology of the -crystallins. The 'Greek key', also known as the 'meander', is a repeating geometric motif that has been used across buildings, decorative arts, jewelry and even clothes for centuries. But, Protein domains are 3 dime. nsp9 sars-cov -barrel structure is a concatenation of two greek key motifs, greek key 1 having a g- topology and greek key 2 a g+ topology ( 30 ), resulting in a six-stranded rh-g- to g+ topology. They occur as the short loop regions between antiparallel hydrogen bonded beta-strands. The vast majority of motifs do not have a common evolutionary origin in spite of many claims to the contrary. The Greek key motifs are the topological signature of many beta-barrels and a majority of beta-sandwich structures. The Greek key motif consists of four antiparallel strands in a sheet where the order of the strands along the polypeptide chain is 4, 1, 2, 3. Notify me when new ads are posted. 8 Page(s). Super-Secondary Structure - Given the number of possible combinations of 1o, 2o, and 3o structures, one might guess that the 3D structure of each protein is quite distinctive. Other [ edit] -sheets (composed of multiple hydrogen-bonded individual -strands) are sometimes considered a secondary or supersecondary structure. A beta-alpha-beta motif is composed of two beta strands joined by an alpha . The fold's Greek-key motif exhibits topological similarities with OB-fold proteins and small protein B but such vestiges have proven insufficient to provide clear insight into Nsp9 function (Egloff et al., 2004). This work has classified Greek keys, based on their hydrogen bonding patterns, into three groups with similar three-dimensional structures, and shows the variability of secondary structure segment length and sequences of Greek keys even within one class. It was the most important symbol utilized in Ancient Greece. Structural motif Motif is also used to describe a consensus primary sequence (implies but does not prove similar tertiary structure) Lecture 4 Biochemistry 4000 Slide 3 Tertiary Structure Simplest classification of tertiary (domain) structure is based upon secondary structures domain: Composed only (primarily) of . What does the Greek key symbolize? It can also represent waves, the four compass points, the four seasons and snakes. a. -helix b. -pleated sheet. Simple supersecondary structures are typically composed of two secondary structures (ie. Results for "greek key" in Buy & Sell in Ontario Showing 1 - 40 of 56 results. Super-secondary structure is simply a combination of secondary structures. Larger motifs such as the greek key will be examined in the sections on tertiary structure and protein folds. Do you know the Greek key . Study supersecondary structure flashcards from jonny howard's university college london class online, or in Brainscape's iPhone or Android app. The resulting structure is a key building block of many RNA secondary . It has been traditionally defined as four beta-strands with '+3,-1,-1' topology . Which of the following best describes a motif A a repetitive supersecondary from BIOL 434 at University of North Carolina, Chapel Hill Study Resources Main Menu The first term is motif, also called a fold or supersecondary structure. The Greek key motif, a terminology based on the pattern and supersecondary features observed in proteins, is a basic theme of many all- proteins ( 45, 46 ). Answer (1 of 6): Thanks for A2A, but I think Ameya Dravid correctly answered your question. phosphorylation and hydrophobicity groups 49) Protein structure. This is where three -helices are further . Supersecondary structures can act as nucleations in the process of protein folding. Large supersecondary structures (ie. This is true. These are combinations of a and/or j8 structure. An updated survey of these structures integrates many early observations and. Supersecondary structures(motifs) are produced by packing side chainsfrom adjacent secondary structural elementsclose to each other. Learn faster with spaced repetition. The conserved . -strands and -helices are symbolized by arrows and cylinders, respectively, and they are numbered Reading Assignment - Section 5 (secondary structure) Name the two common types of secondary structure. ( d) schematic representation of nsp9 topology. Today, the Greek Key is known to symbolize 'eternity' and 'unity' because of the continuous line pattern. d. An unfolded region of a protein. Onethird of all known protein structures can be classified into ten protein folds . Its convoluted path resembled wave paths, symbolizing infinity or the eternal flow of things. The ability of a recent Monte Carlo-based procedure to generate the 3D structures of eight polypeptides that correspond to units of supersecondary structure and threestranded antiparallel beta sheet is explored. Which of the following supersecondary structures (motifs) is a Greek key motif: Greek Key motif. -sheets (composed of multiple hydrogen-bonded individual -strands) are sometimes considered a secondary or supersecondary structure.

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