title: In silico discovery of enzyme-substrate specificity-determining residue clusters.
abstract: The binding between an enzyme and its substrate is highly specific, despite the fact that many different enzymes show significant sequence and structure similarity. There must be, then, substrate specificity-determining residues that enable different enzymes to recognize their unique substrates. We reason that a coordinated, not independent, action of both conserved and non-conserved residues determine enzymatic activity and specificity. Here, we present a surface patch ranking (SPR) method for in silico discovery of substrate specificity-determining residue clusters by exploring both sequence conservation and correlated mutations. As case studies we apply SPR to several highly homologous enzymatic protein pairs, such as guanylyl versus adenylyl cyclases, lactate versus malate dehydrogenases, and trypsin versus chymotrypsin. Without using experimental data, we predict several single and multi-residue clusters that are consistent with previous mutagenesis experimental results. Most single-residue clusters are directly involved in enzyme-substrate interactions, whereas multi-residue clusters are vital for domain-domain and regulator-enzyme interactions, indicating their complementary role in specificity determination. These results demonstrate that SPR may help the selection of target residues for mutagenesis experiments and, thus, focus rational drug design, protein engineering, and functional annotation to the relevant regions of a protein.
authors.affiliation: Computational Biology Institute, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831, USA.
authors.forename: Gong-Xin
authors.initials: GX
authors.lastname: Yu
authors.forename: Byung-Hoon
authors.initials: BH
authors.lastname: Park
authors.forename: Praveen
authors.initials: P
authors.lastname: Chandramohan
authors.forename: Rajesh
authors.initials: R
authors.lastname: Munavalli
authors.forename: Al
authors.initials: A
authors.lastname: Geist
authors.forename: Nagiza F
authors.initials: NF
authors.lastname: Samatova
mesh_terms: D000262:Adenylyl Cyclases / Q000502:physiology; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry* / Q000502:physiology*; D000818:Animals; D001665:Binding Sites / Q000502:physiology; D002417:Cattle; D002918:Chymotrypsin / Q000502:physiology; D019295:Computational Biology; D018360:Crystallography, X-Ray; D004798:Enzymes / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D006162:Guanylate Cyclase / Q000502:physiology; D007770:L-Lactate Dehydrogenase / Q000502:physiology; D008291:Malate Dehydrogenase / Q000502:physiology; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity / Q000502:physiology; D014357:Trypsin / Q000737:chemistry / Q000502:physiology
chemical_list: D000596:Amino Acids; D004798:Enzymes; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D002918:Chymotrypsin; D014357:Trypsin; D000262:Adenylyl Cyclases; D006162:Guanylate Cyclase