title: The invariant F283 and its strategic position in the hydrophobic cleft of Streptomyces jumonjinensis isopenicillin N synthase active site are functionally important.
abstract: Isopenicillin N synthase (IPNS) and related non-haem iron-binding enzymes including deacetoxycephalosporin C synthase (DAOCS) are proposed to have structurally similar active centers. Sequence alignment and computational structural analyses of predicted structures revealed 11 highly conserved hydrophobic amino acid residues in 134 IPNS-related enzymes form a contiguous hydrophobic patch in the IPNS active center, wherein F283 is strategically positioned. The investigation of single and double mutations at F283, adjacent (L284) and proximal sites (N285 and S216) of Streptomyces jumonjinensis IPNS advocate the explicit importance of the phenyl ring at position 283. A similarly placed phenylalanine (F264) in DAOCS was found to be also crucial for its enzyme activity.
authors.affiliation: Department of Microbiology, Faculty of Medicine, National University of Singapore, 5 Science Drive 2, Singapore, 117597, Singapore.
authors.forename: E
authors.initials: E
authors.lastname: Wong
authors.forename: J
authors.initials: J
authors.lastname: Sim
authors.forename: T S
authors.initials: TS
authors.lastname: Sim
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D020134:Catalytic Domain / Q000235:genetics; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D015870:Gene Expression; D005798:Genes, Bacterial; D019751:Intramolecular Transferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D046915:Penicillin-Binding Proteins; D010649:Phenylalanine / Q000737:chemistry; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics
chemical_list: D017931:DNA Primers; D046915:Penicillin-Binding Proteins; D011993:Recombinant Fusion Proteins; D010649:Phenylalanine; D010088:Oxidoreductases; C038370:isopenicillin N synthetase; D019751:Intramolecular Transferases; C038371:deacetoxycephalosporin C synthetase