TY - JOUR
T1 - Novel mutations in katG gene of a clinical isolate of isoniazid-resistant Mycobacterium tuberculosis
AU - Purkan,
AU - Ihsanawati,
AU - Syah, Yana M.
AU - Retnoningrum, Debbie S.
AU - Noer, Achmad S.
AU - Shigeoka, Shigeru
AU - Natalia, Dessy
PY - 2012/2
Y1 - 2012/2
N2 - Most of isoniazid-resistant Mycobacterium tuberculosis evolved due to mutation in the katG gene encoding catalase-peroxidase. A set of new mutations, namely T1310C, G1388T, G1481A, T1553C, and A1660G, which correspond to amino acid substitutions of L437P, R463L, G494D, I518T, and K554E, in the katG gene of the L10 clinical isolate M. tuberculosis was identified. The wild-type and mutant KatG proteins were expressed in Escherichia coli BL21(DE3) as a protein of 80 kDa based on sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis. The mutant KatG protein exhibited catalase and peroxidase activities of 4. 6% and 24. 8% toward its wild type, respectively, and retained 19. 4% isoniazid oxidation activity. The structure modelling study revealed that these C-terminal mutations might have induced formation of a new turn, perturbing the active site environment and also generated new intramolecular interactions, which could be unfavourable for the enzyme activities.
AB - Most of isoniazid-resistant Mycobacterium tuberculosis evolved due to mutation in the katG gene encoding catalase-peroxidase. A set of new mutations, namely T1310C, G1388T, G1481A, T1553C, and A1660G, which correspond to amino acid substitutions of L437P, R463L, G494D, I518T, and K554E, in the katG gene of the L10 clinical isolate M. tuberculosis was identified. The wild-type and mutant KatG proteins were expressed in Escherichia coli BL21(DE3) as a protein of 80 kDa based on sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis. The mutant KatG protein exhibited catalase and peroxidase activities of 4. 6% and 24. 8% toward its wild type, respectively, and retained 19. 4% isoniazid oxidation activity. The structure modelling study revealed that these C-terminal mutations might have induced formation of a new turn, perturbing the active site environment and also generated new intramolecular interactions, which could be unfavourable for the enzyme activities.
KW - Mycobacterium tuberculosis
KW - catalase-peroxidase
KW - clinical isolate
KW - isoniazid resistance
KW - katG
UR - http://www.scopus.com/inward/record.url?scp=84855581107&partnerID=8YFLogxK
U2 - 10.2478/s11756-011-0162-7
DO - 10.2478/s11756-011-0162-7
M3 - Article
AN - SCOPUS:84855581107
SN - 0006-3088
VL - 67
SP - 41
EP - 47
JO - Biologia (Poland)
JF - Biologia (Poland)
IS - 1
ER -