Open AccessMonoclonal antibodies to mycobacterial DNA gyrase A inhibit DNA supercoiling activity
Author(s) -
Manjunatha U. H.,
Mahadevan S.,
Visweswariah Sandhya S.,
Nagaraja V.
Publication year - 2001
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2001.02077.x
Subject(s) - dna gyrase , dna supercoil , monoclonal antibody , epitope , mycobacterium smegmatis , microbiology and biotechnology , biology , dna , chemistry , mycobacterium tuberculosis , escherichia coli , antibody , biochemistry , genetics , gene , tuberculosis , dna replication , medicine , pathology
DNA gyrase is an essential type II topoisomerase found in bacteria. We have previously characterized DNA gyrase from Mycobacterium tuberculosis and Mycobacterium smegmatis . In this study, several monoclonal antibodies were generated against the gyrase A subunit (GyrA) of M. smegmatis . Three, MsGyrA:C3, MsGyrA:H11 and MsGyrA:E9, were further analyzed for their interaction with the enzyme. The monoclonal antibodies showed high degree of cross‐reactivity with both fast‐growing and slow‐growing mycobacteria. In contrast, none recognized Escherichia coli GyrA. All the three monoclonal antibodies were of IgG 1 isotype falling into two distinct types with respect to epitope recognition and interaction with the enzyme. MsGyrA:C3 and MsGyrA:H11 IgG, and their respective Fab fragments, inhibited the DNA supercoiling activity catalyzed by mycobacterial DNA gyrase. The epitope for the neutralizing monoclonal antibodies appeared to involve the region towards the N‐terminus (residues 351–415) of the enzyme in a conformation‐dependent manner. These monoclonal antibodies would serve as valuable tools for structure–function analysis and immunocytological studies of mycobacterial DNA gyrase. In addition, they would be useful for designing peptide inhibitors against DNA gyrase.