Premium
A catalytic role for threonine‐12 of E. coli asparaginase II as established by site‐directed mutagenesis
Author(s) -
Harms E.,
Wehner A.,
Aung H.-P.,
Röhm K.H.
Publication year - 1991
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(91)80723-g
Subject(s) - threonine , enzyme , mutagenesis , mutant , biochemistry , site directed mutagenesis , chemistry , alanine , mutation , asparaginase , protein quaternary structure , substrate (aquarium) , active site , biology , serine , amino acid , protein subunit , genetics , gene , ecology , lymphoblastic leukemia , leukemia
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.