title: Structural role of exon-coded fragment of polypeptide chains in selected enzymes.
abstract: This paper discusses the structural role of fragments encoded by individual exons in proteins. Selected enzymes (hydrolases, transferases, ligases) reveal the presence of at least one exon fragment whose contribution to the protein's hydrophobic core is in line with theoretical expectations. This phenomenon is confirmed by quantitative analysis of the hydrophobicity density distribution in protein molecules. Results are compared with a 3D Gaussian function, treated as an "idealized" distribution of hydrophobicity density, with the highest values observed near the center of the molecule and near-zero values on its surface. At least one accordant exon fragment has been identified in each of the proteins subjected to analysis. On the basis of these results the authors propose that accordant exons are responsible for tertiary structural stabilization of proteins by ensuring the generation of a stable hydrophobic core.
authors.affiliation: Department of Bioinformatics and Telemedicine, Medical College-Jagiellonian University, Lazarza 16, 31-530 Krakow, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Piwowar
authors.affiliation: Department of Bioinformatics and Telemedicine, Medical College-Jagiellonian University, Lazarza 16, 31-530 Krakow, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Banach
authors.affiliation: Chair of Medical Biochemistry, Medical College-Jagiellonian University, Kopernika 7, 31-034 Krakow, Poland.
authors.forename: Leszek
authors.initials: L
authors.lastname: Konieczny
authors.affiliation: Department of Bioinformatics and Telemedicine, Medical College-Jagiellonian University, Lazarza 16, 31-530 Krakow, Poland. Electronic address: myroterm@cyf-kr.edu.pl.
authors.forename: Irena
authors.initials: I
authors.lastname: Roterman
mesh_terms: D000596:Amino Acids / Q000235:genetics / Q000378:metabolism; D004798:Enzymes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005091:Exons / Q000235:genetics*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D016366:Open Reading Frames; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D004798:Enzymes; D010455:Peptides
keywords: Exon; Fuzzy oil drop model; Hydrophobicity