| http://purl.uniprot.org/citations/16650857 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/16650857 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/16650857 | http://www.w3.org/2000/01/rdf-schema#comment | "N-Acylamino acid racemase (NAAAR) and N-carbamoyl-D-amino-acid amidohydrolase (D-NCAase) are important biocatalysts for producing enantiopure alpha-amino acids. NAAAR forms an octameric assembly and displays induced fit movements upon substrate binding, while D-NCAase is a tetramer that does not change conformation in the presence of a ligand. To investigate the effects of introducing potentially stabilizing S-S bridges in these different multimeric enzymes, cysteine residues predicted to form inter or intra-subunit disulfide bonds were introduced by site-directed mutagenesis. Inter-subunit S-S bonds were formed in two NAAAR variants (A68C-D72C and P60C-Y100C) and two d-NCAase variants (A302C and P295C-F304C). Intra-subunit S-S bonds were formed in two additional NAAAR variants (E149C-A182C and V265C). Crystal structures of NAAARs variants show limited deviations from the wild-type overall tertiary structure. An apo A68C-D72C subunit differs from the wild-type enzyme, in which it has an ordered lid loop, resembling ligand-bound NAAAR. The structures of A222C and A302C D-NCAases are nearly identical to the wild-type enzyme. All mutants with inter-subunit bridges had increases in thermostability. Compared with the wild-type enzyme, A68C-D72C NAAAR showed similar kcat/Km ratios, whereas mutant D-NCAases demonstrated increased kcat/Km ratios at high temperatures (A302C: 4.2-fold at 65 degrees C). Furthermore, molecular dynamic simulations reveal that A302C substantially sustains the fine-tuned catalytic site as temperature increases, achieving enhanced activity."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.org/dc/terms/identifier | "doi:10.1016/j.jmb.2006.03.063"xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.org/dc/terms/identifier | "doi:10.1016/j.jmb.2006.03.063"xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Liu J.S."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Liu J.S."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Wang W.C."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Wang W.C."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Hsu W.H."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Hsu W.H."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Shih C.H."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Shih C.H."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "You J.Y."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "You J.Y."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Chiu W.C."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Chiu W.C."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Hsu S.K."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Hsu S.K."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Hwang J.K."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/author | "Hwang J.K."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/date | "2006"xsd:gYear |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/date | "2006"xsd:gYear |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/name | "J. Mol. Biol."xsd:string |
| http://purl.uniprot.org/citations/16650857 | http://purl.uniprot.org/core/name | "J. Mol. Biol."xsd:string |