Novel Mutations in the katG Gene in Isoniazid Resistant Mycobacterium tuberculosis Isolate
Abstract: Isoniazid (INH)
resistance in Mycobacterium tuberculosis is commonly associated with mutations
in katG encoding catalase-peroxidase. A
clinical isolate of M. tuberculosis L21 exhibits isoniazid resistant
phenotype. A 2.2 kb DNA fragment of katG
gene from the L21 isolate had been cloned and characterized. The L21 katG gene has four point mutations,
namely T898C; G1388T; T1997C; C2035T; and one G2203 deletion. The in silico translation analysis of the katG
mutant suggests that the mutation results in a truncated protein lacking of 62
C-terminal amino acids with three amino acid substitutions, Trp300Arg, Arg463Leu,
and Ile666Thr. The structural model superposition of the mutant protein with
the full length protein suggests that the mutant losses an ability to form a
dimer structure, and also posseses a distortion of intermolecular interactions
in the substrate binding channel.
Author: Purkan, Ihsanawati,
Debbie Soefie Retnoningrum, Yana Maolana Syah
Journal Code: jpmatematikagg130003
