scholarly journals Secondary Structure Preferences of Mn2+ Binding Sites in Bacterial Proteins

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Tatyana Aleksandrovna Khrustaleva
Keyword(s):  
Amino Acid ◽  
Secondary Structure ◽  
Glutamic Acid ◽  
Gc Content ◽  
Alpha Helix ◽  
Random Coil ◽  
Amino Acid Residues ◽  
Alpha Helices ◽  
Beta Strand ◽  
Genomic Gc Content

3D structures of proteins with coordinated Mn2+ ions from bacteria with low, average, and high genomic GC-content have been analyzed (149 PDB files were used). Major Mn2+ binders are aspartic acid (6.82% of Asp residues), histidine (14.76% of His residues), and glutamic acid (3.51% of Glu residues). We found out that the motif of secondary structure “beta strand-major binder-random coil” is overrepresented around all the three major Mn2+ binders. That motif may be followed by either alpha helix or beta strand. Beta strands near Mn2+ binding residues should be stable because they are enriched by such beta formers as valine and isoleucine, as well as by specific combinations of hydrophobic and hydrophilic amino acid residues characteristic to beta sheet. In the group of proteins from GC-rich bacteria glutamic acid residues situated in alpha helices frequently coordinate Mn2+ ions, probably, because of the decrease of Lys usage under the influence of mutational GC-pressure. On the other hand, the percentage of Mn2+ sites with at least one amino acid in the “beta strand-major binder-random coil” motif of secondary structure (77.88%) does not depend on genomic GC-content.

scholarly journals The Influence of Flanking Secondary Structures on Amino Acid Content and Typical Lengths of 3/10 Helices

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Vladislav Victorovich Khrustalev ◽  
Eugene Victorovich Barkovsky ◽  
Tatyana Aleksandrovna Khrustaleva
Keyword(s):  
Amino Acid ◽  
Gc Content ◽  
Amino Acid Content ◽  
Alpha Helix ◽  
Major Elements ◽  
Random Coil ◽  
Amino Acid Residues ◽  
Alpha Helices ◽  
Beta Strand ◽  
Bacterial Proteins

We used 3D structures of a highly redundant set of bacterial proteins encoded by genes of high, average, and low GC-content. Four types of connecting bridges—regions situated between any of two major elements of secondary structure (alpha helices and beta strands)—containing a pure random coil were compared with connecting bridges containing 3/10 helices. We included discovered trends in the original “VVTAK Connecting Bridges” algorithm, which is able to predict more probable conformation for a given connecting bridge. The highest number of significant differences in amino acid usage was found between 3/10 helices containing bridges connecting two beta strands (they have increased Phe, Tyr, Met, Ile, Leu, Val, and His usages but decreased usages of Asp, Asn, Gly, and Pro) and those without 3/10 helices. The typical (most common) length of 3/10 helices situated between two beta strands and between beta strand and alpha helix is equal to 5 amino acid residues. The preferred length of 3/10 helices situated between alpha helix and beta strand is equal to 3 residues. For 3/10 helices situated between two alpha helices, both lengths (3 and 5 amino acid residues) are typical.

scholarly journals Cystatin. Amino acid sequence and possible secondary structure

1984 ◽  
Vol 217 (3) ◽  
pp. 813-817 ◽  
Author(s):  
C Schwabe ◽  
A Anastasi ◽  
H Crow ◽  
J K McDonald ◽  
A J Barrett
Keyword(s):  
Amino Acid ◽  
Secondary Structure ◽  
Amino Acid Sequence ◽  
Tight Binding ◽  
Alpha Helix ◽  
Egg White ◽  
Striking Similarity ◽  
Cysteine Proteinases ◽  
Amino Acid Residues ◽  
Beta Structure

The amino acid sequence of cystatin, the protein from chicken egg-white that is a tight-binding inhibitor of many cysteine proteinases, is reported. Cystatin is composed of 116 amino acid residues, and the Mr is calculated to be 13 143. No striking similarity to any other known sequence has been detected. The results of computer analysis of the sequence and c.d. spectrometry indicate that the secondary structure includes relatively little alpha-helix (about 20%) and that the remainder is mainly beta-structure.

scholarly journals Epiplasts: Membrane Skeletons and Epiplastin Proteins in Euglenids, Glaucophytes, Cryptophytes, Ciliates, Dinoflagellates, and Apicomplexans

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Ursula Goodenough ◽  
Robyn Roth ◽  
Thamali Kariyawasam ◽  
Amelia He ◽  
Jae-Hyeok Lee
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Amino Acid ◽  
Secondary Structure ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Random Coil ◽  
Cell Cortex ◽  
Tail Domain ◽  
Membrane Skeletons

ABSTRACTAnimals and amoebae assemble actin/spectrin-based plasma membrane skeletons, forming what is often called the cell cortex, whereas euglenids and alveolates (ciliates, dinoflagellates, and apicomplexans) have been shown to assemble a thin, viscoelastic, actin/spectrin-free membrane skeleton, here called the epiplast. Epiplasts include a class of proteins, here called the epiplastins, with a head/medial/tail domain organization, whose medial domains have been characterized in previous studies by their low-complexity amino acid composition. We have identified two additional features of the medial domains: a strong enrichment of acid/base amino acid dyads and a predicted β-strand/random coil secondary structure. These features have served to identify members in two additional unicellular eukaryotic radiations—the glaucophytes and cryptophytes—as well as additional members in the alveolates and euglenids. We have analyzed the amino acid composition and domain structure of 219 epiplastin sequences and have used quick-freeze deep-etch electron microscopy to visualize the epiplasts of glaucophytes and cryptophytes. We define epiplastins as proteins encoded in organisms that assemble epiplasts, but epiplastin-like proteins, of unknown function, are also encoded in Insecta, Basidiomycetes, andCaulobactergenomes. We discuss the diverse cellular traits that are supported by epiplasts and propose evolutionary scenarios that are consonant with their distribution in extant eukaryotes.IMPORTANCEMembrane skeletons associate with the inner surface of the plasma membrane to provide support for the fragile lipid bilayer and an elastic framework for the cell itself. Several radiations, including animals, organize such skeletons using actin/spectrin proteins, but four major radiations of eukaryotic unicellular organisms, including disease-causing parasites such asPlasmodium, have been known to construct an alternative and essential skeleton (the epiplast) using a class of proteins that we term epiplastins. We have identified epiplastins in two additional radiations and present images of their epiplasts using electron microscopy. We analyze the sequences and secondary structure of 219 epiplastins and present an in-depth overview and analysis of their known and posited roles in cellular organization and parasite infection. An understanding of epiplast assembly may suggest therapeutic approaches to combat infectious agents such asPlasmodiumas well as approaches to the engineering of useful viscoelastic biofilms.

Protein Sequence and Structure of N-terminal Amino Acids of Subunit Delta of Spinach Photosynthetic ATP-Synthase CF1

1987 ◽  
Vol 42 (11-12) ◽  
pp. 1231-1238 ◽  
Author(s):  
Richard J. Berzborn ◽  
Werner Finke ◽  
Joachim Otto ◽  
Helmut E . Meyer
Keyword(s):  
Secondary Structure ◽  
Atp Synthase ◽  
Protein Sequence ◽  
Alpha Helix ◽  
Amino Acid Residues ◽  
E Coli ◽  
Helical Wheel ◽  
Terminal Amino ◽  
Amphipathic Alpha Helix ◽  
Structure Calculations

Chloroplast ATP-synthase (CF1) subunit delta (δ) has been isolated from spinach thylakoids in the presence of SDS. By automated Edman degradation and online analysis of PTH derivatives the 35 N-terminal amino acid residues were sequenced. The mature protein starts with: NH2-Val-Asp-Ser-Thr-Ala-Ser-Arg-Tyr-Ala-. This protein sequence allows alignment of spinach δ with the sequences of Z. mays 25 kDa polypeptide, the δ subunit of Rps. blastica, Rsp. rubrum and E. coli F1, and of bovine OSCP, but not with mitochondrial δ. Secondary structure calculations and helical wheel plots reveal a conserved secondary structure. The analyzed N-terminal sequences probably build a short amphipathic alpha helix with two adjacent turns. The such aligned polar residues around Tyr8 of subunit δ are suitable to channel protons.

Bioinformatic Analysis and Characteristics of Glycoprotein L(gL) Encoded by UL1 Gene of Duck Plague Virus

2013 ◽  
Vol 647 ◽  
pp. 250-257
Author(s):  
Ling Jie Zuo ◽  
An Chun Cheng ◽  
Ming Shu Wang
Keyword(s):  
Secondary Structure ◽  
Physicochemical Properties ◽  
Evolutionary Relationship ◽  
Alpha Helix ◽  
Bioinformatic Analysis ◽  
Random Coil ◽  
Phosphorylation Sites ◽  
Duck Plague Virus ◽  
Online Tools ◽  
Glycosylation Sites

Glycoprotein L(gL) is encoded by UL1 gene of duck plague virus (DPV). Through predicting and analyzing the structure and physicochemical properties of DPV gL protein by using some software and online tools to gain more information of DPV gL protein. The phylogenetic tree shows that DPV gL protein has close evolutionary relationship with the genus Simplexvirus. The online analysis of the physicochemical properties demonstrates that the protein has ten potential phosphorylation sites and five potential O-linked glycosylation sites, and without both the signal peptide and the transmembrance region. In addition, the subcellular localization of gL protein largely locates at mitochondrial with 47.8%. The secondary structure results reveal that random coil dominate among secondary structure elements followed by alpha helix, extended strand and β-turn for all sequences. All the data will help a basis for further functional and physiological features study of the DPV gL protein.

Primary Structure and Anticandidal Activity of the Major Histatin from Parotid Secretion of the Subhuman Primate, Macaca fascicularis

1990 ◽  
Vol 69 (11) ◽  
pp. 1717-1723 ◽  
Author(s):  
T. Xu ◽  
E. Telser ◽  
R.F. Troxler ◽  
F.G. Oppenheim
Keyword(s):  
Amino Acid ◽  
High Performance ◽  
Macaca Fascicularis ◽  
Sequence Similarity ◽  
Gel Filtration ◽  
Alpha Helix ◽  
Reversed Phase ◽  
Amino Acid Residues ◽  
Beta Turns ◽  
Anticandidal Activity

A major macaque histatin (M-histatin 1) from the parotid secretion of the subhuman primate, Macaca fascicularis, was isolated by gel filtration on Bio-Gel P-2 and purified to homogeneity by reversed-phase high-performance liquid chromatography on a TSK-ODS C18 column. The complete amino acid sequence of M-histatin 1, determined by automated Edman degradation, is: 1 10 20 Asp-Pse-His-Glu-Glu-Arg-His-His-Gly-Arg-His-Gly-His-His-Lys-Tyr-Gly-Arg-Lys-Phe 21 30 38 His-Glu-Lys-His-His-Ser-His-Arg-Gly-Tyr-Arg-Ser-Asn-Tyr-Leu-Tyr-Asp-Asn M-histatin 1 contains 38 amino acid residues, a phosphoserine at residue 2, has a molecular weight of 4881.8, a calculated pI of 8.5, and histidine forms 26.3% of the mass. The hydropathicity plot of M-histatin 1 predicts that the molecule is entirely hydrophilic, and Chou-Fasman secondary prediction indicates that the polypeptide is devoid of alpha-helix and beta-sheet conformation in aqueous solutions but contains a series of beta turns. M-histatin 1 includes a six-amino-acid insert (residue 10-15) not present in human histatins and, with the introduction of gaps to maximize homology, it displays 89% and 91% sequence similarity with human histatins 1 and 3, respectively. M-histatin 1 exhibited fungicidal and fungistatic effects against the dimorphic pathogen, Candida albicans, in three separate bioassays. Its anticandidal effects were comparable with or greater than those of human histatins 1, 3, and 5. M-histatins 2, 3, and 4 were not sequenced directly because insufficient materials were available, but the amino acid composition of M-histatin 3 was nearly identical to that of the N-terminal 20 amino acid residues of M-histatin 1. There appears to be only one major histatin in macaque parotid secretion in contrast to the family of histatins in human parotid and submandibular secretions, and the significance of this in the context of evolution and mechanism of action in anticandidal assays is discussed.

Amino acid sequence restriction in relation to proteolysis

1983 ◽  
Vol 3 (3) ◽  
pp. 225-232 ◽  
Author(s):  
Hans Jórnvall ◽  
Bengt Persson
Keyword(s):  
Amino Acid ◽  
Secondary Structure ◽  
Amino Acid Sequence ◽  
Distribution Patterns ◽  
Amino Acid Residues ◽  
Individual Protein ◽  
Proteolytic Cleavages ◽  
N Proteins

Distributions of amino acid residues in proteins show that proline is overrepresented in sequence positions following two basic residues ({LysArg}−{LysArg}), i.e. at sites similar to those susceptible to proteolytic cleavages of hormonal pro-forms. Conformational correlations further show that {LysArg}−{LysArg}-Pro sequences are often (8/11) not adiacent to elements of secondary structure, whereas the opposite applies to {LysArg}−{LysArg}-nonPro sequences (82/103 adjacent to elements of secondary structure). These distribution patterns from proteins in general also seem applicable in individual protein groups as demonstrated for some dehydrogenases. It appears possible that {LysArg}−{LysArg}-nonPro constitutes a restricted sequence, n proteins, and that proline, in addition to elements of secondary structure, contributes a means of avoiding unacceptable proteolytic processings of proteins in general.

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