A catalytic role for threonine‐12 of E. coli asparaginase II as established by site‐directed mutagenesis

FEBS Letters

Wehner, A.²  Röhm, K.H.²  Aung, H.-P.²  Harms, E.¹ 

[1] Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA;Institut für Physiologische Chemie, Philipps Universität, D-3550 Marburg, Germany

关键词: Asparaginase II;    Mechanism;    Catalysis;    Thr-12;    Mutagenesis;    (E. coli);   

DOI  :  10.1016/0014-5793(91)80723-G

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A threonine-12 to alanine mutant of E. coli asparaginase II (EC 3.5.1.1) has less than 0.01% of the activity of wild-type enzyme. Both tertiary and quaternary structure of the enzyme are essentially unaffected by the mutation; thus the activity loss seems to be the result of a direct impairment of catalytic function. As aspartate is still bound by the mutant enzyme, Thr-12 appears not be involved in substrate binding.

【 授权许可】

Unknown