Tsuru D, Oda N, Matsuo Y, Ishikawa S, Ito K, Yoshimoto T
Department of Applied Microbial Technology, Kumamoto Institute of Technology, Japan.
Biosci Biotechnol Biochem. 1997 Aug;61(8):1354-7. doi: 10.1271/bbb.61.1354.
The role of cysteine residues for structure and function of formaldehyde dehydrogenase from Pseudomonas putida was analysed by amino acid sequence comparison, homology-based structure modeling, site-directed mutagenesis, and chemical modification. Five out of seven cysteine residues found in the enzyme were concluded to coordinate with an active site zinc (Cys-46) and structural zinc atoms (Cys-97, -100, -103, and -111) from the sequence comparison with other Zn-containing medium-chain alcohol dehydrogenase homologues. The three-dimensional structure model based on the known structure of the horse liver E-type alcohol dehydrogenase (ADH) indicated that Cys-257 is located very far from the active site Zn and NAD+ binding region, suggesting that Cys-257 does not participate in the enzyme reaction. The structure also suggested that Cys-166 does not coordinate to active site Zn, but Asp-169 functions as a Zn-ligand, instead.
通过氨基酸序列比较、基于同源性的结构建模、定点诱变和化学修饰，分析了恶臭假单胞菌甲醛脱氢酶中半胱氨酸残基对其结构和功能的作用。通过与其他含锌中链醇脱氢酶同系物的序列比较，得出该酶中七个半胱氨酸残基中的五个与一个活性位点锌（Cys-46）和结构锌原子（Cys-97、-100、-103和-111）配位。基于马肝E型醇脱氢酶（ADH）已知结构的三维结构模型表明，Cys-257距离活性位点锌和NAD+结合区域非常远，这表明Cys-257不参与酶反应。该结构还表明，Cys-166不与活性位点锌配位，相反，Asp-169作为锌配体发挥作用。
