Open AccessAmino acid alterations essential for increasing the catalytic activity of the nylon‐oligomer‐degradation enzyme of Flavobacterium sp.
Author(s) -
KATO Ko,
FUJIYAMA Kazuhito,
HATANAKA Haruyo Sawai,
PRIYAMBADA Irfan Dwidya,
NEGORO Seiji,
URABE Itaru,
OKADA Hirosuke
Publication year - 1991
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1991.tb21063.x
Subject(s) - dimer , open reading frame , biochemistry , amino acid , enzyme , flavobacterium , chemistry , gene , hydrolase , peptide sequence , biology , stereochemistry , genetics , bacteria , pseudomonas , organic chemistry
The structural genes of two homologous enzymes, 6‐aminohexanoate‐dimer hydrolase (EII; nylB ) and its evolutionally related protein EII′ ( nylB′ ) of Flavobacterium sp. KI72 have an open reading frame encoding a peptide of 392 amino acids, of which 47 are different, and conserved restriction sites. The specific activity of EII towards 6‐aminohexanoate dimer is about 1000‐fold that of EII'. Construction of various hybrid genes obtained by exchanging fragments flanked by conserved restriction sites of the two genes demonstrated that two amino acid replacements in the EII′ enzyme, i.e. Gly181 → Asp (EII type) and His266 → Asn (EII type), enhanced the activity toward 6‐aminohexanoate dimer 1000‐fold.