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Biomedical subjects

I A Adzhubei

Publications and source records attributed to I A Adzhubei.

7 recordsLinked to original sources

ISSD Version 2.0: taxonomic range extended.

Two more organisms from different taxonomic groups were added to a new version of the Integrated Sequence-Structure Database (ISSD). ISSD serves as an integrated source of sequence and structure information for the analysis of correlations between mRNA synonymous codon usage and three-dimensional structure of the encoded proteins. ISSD now holds 88 non-homologous Escherichia coli proteins and 25 yeast Saccharomyces cerevisiae proteins in addition to the expanded set of mammalian proteins, which includes 166 proteins (107 in ISSD Version 1.0). Comparison of ISSD sequences with organism-specific codon usage data derived from CUTG database shows that it is a representative subset of the GenBank coding sequences data. Preliminary results of the statistical analysis confirm that sequence-structure correlations observed by us earlier are also present in the upgraded ISSD (Version 2.0), including bacterial and yeast proteins. The ISSD Version 2.0 release includes an improved Web-based data search and retrieval system and is accessible via URL http://www.protein.bio.msu.su/issd/. ISSD can be also accessed at ExPASy, URL http://www.expasy.ch/swissmod/swiss-model.htm l

Animals↗

An Integrated Sequence-Structure Database incorporating matching mRNA sequence, amino acid sequence and protein three-dimensional structure data.

We have constructed a non-homologous database, termed the Integrated Sequence-Structure Database (ISSD) which comprises the coding sequences of genes, amino acid sequences of the corresponding proteins, their secondary structure and straight phi,psi angles assignments, and polypeptide backbone coordinates. Each protein entry in the database holds the alignment of nucleotide sequence, amino acid sequence and the PDB three-dimensional structure data. The nucleotide and amino acid sequences for each entry are selected on the basis of exact matches of the source organism and cell environment. The current version 1.0 of ISSD is available on the WWW at http://www.protein.bio.msu.su/issd/ and includes 107 non-homologous mammalian proteins, of which 80 are human proteins. The database has been used by us for the analysis of synonymous codon usage patterns in mRNA sequences showing their correlation with the three-dimensional structure features in the encoded proteins. Possible ISSD applications include optimisation of protein expression, improvement of the protein structure prediction accuracy, and analysis of evolutionary aspects of the nucleotide sequence-protein structure relationship.

Algorithms↗

Non-random usage of 'degenerate' codons is related to protein three-dimensional structure.

We report an analysis of a novel sequence-structure database of mammalian proteins incorporating nucleotide sequences of the exon regions of their genes together with protein sequence and structural information. We find that synonymous codon families (i.e. coding the same residue) have non-random codon distribution frequencies between protein secondary structure types. Their structural preferences are related to the third, 'silent' nucleotide position in a codon. We also find that some synonymous codons show very different or even opposite structural preferences at the N- or C-termini of structure fragments, relative to those observed for their amino acid residues.

Animals↗

Scanning microcalorimetry and circular dichroism study of melting of the natural polypeptides in the left-handed helical conformation.

It has been shown that in aqueous solution histone H1 and H5 C-terminal fragments and peptide hormones beta-endorphin and ACTH adopt preferably the left-handed helical conformation of the poly-L-proline II type. Scanning microcalorimetry and circular dichroism have been used to show that the linear temperature dependence of CD maximum amplitude and partial heat capacity value are broken in the temperature interval between 50 and 60 degrees C, after which [C]p reaches the constant level. It was proposed to be due to noncooperative disordering of the conformation caused by the destruction of the polypeptide hydration shell.

Adrenocorticotropic Hormone↗

Natural polypeptides in left-handed helical conformation. A circular dichroism study of the linker histones' C-terminal fragments and beta-endorphin.

Circular dichroism has been used to investigate the histone H1 and H5 C-terminal fragments and beta-endorphin conformation. It has been shown that in aqueous solution these polypeptides preferably adopt the left-handed helical conformation of the poly-L-proline II type. A break in the linear temperature dependence of the CD value was found in the temperature interval between 50 and 55 degrees C. It was proposed to be due to non-cooperative disordering of the conformation caused by the destruction of the hydration shell.

Animals↗

Nonuniform size distribution of nascent globin peptides, evidence for pause localization sites, and a contranslational protein-folding model.

Examination of nascent globin peptides accumulating in vitro during globin synthesis in rabbit reticulocyte lysates was carried out. A view was supported that nonrandom distribution of codons with different usage frequencies in mRNA may determine the messenger's translation kinetics. Regions of reduced translation of alpha- and beta-globin polypeptide chains were localized, and the cotranslational protein-folding model suggested previously was substantiated. An active conjunction of synthesis and folding of proteins was proposed as one of the main destinations of a translation nonuniformity.

Animals↗