0469556 - ÚOCHB 2017 RIV GB eng J - Článek v odborném periodiku
Miggiano, R. - Perugino, G. - Ciaramella, M. - Serpe, M. - Rejman, Dominik - Páv, Ondřej - Pohl, Radek - Garavaglia, S. - Lahiri, S. - Rizzi, M. - Rossi, F.
Crystal structure of Mycobacterium tuberculosis O-6-methylguanine-DNA methyltransferase protein clusters assembled on to damaged DNA.
Biochemical Journal. Roč. 473, č. 2 (2016), s. 123-133. ISSN 0264-6021. E-ISSN 1470-8728
GRANT EU: European Commission(XE) 241587 - SYSTEMTB
Institucionální podpora: RVO:61388963
Klíčová slova: DNA repair * DNA-binding protein * Mycobacterium tuberculosis * O-6-methylguanine-DNA methyltransferase * co-operativity * crystal structure
Kód oboru RIV: CE - Biochemie
Impakt faktor: 3.797, rok: 2016 ; AIS: 1.527, rok: 2016
DOI: https://doi.org/10.1042/BJ20150833

Mycobacterium tuberculosis O-6-methylguanine-DNA methyltransferase (MtOGT) contributes to protect the bacterial GC-rich genome against the pro-mutagenic potential of O-6-methylated guanine in DNA. Several strains of M. tuberculosis found worldwide encode a point-mutated O-6-methylguanine-DNA methyltransferase (OGT) variant (MtOGT-R37L), which displays an arginine-to-leucine substitution at position 37 of the poorly functionally characterized N-terminal domain of the protein. Although the impact of this mutation on the MtOGT activity has not yet been proved in vivo, we previously demonstrated that a recombinant MtOGT-R37L variant performs a suboptimal alkylated-DNA repair in vitro, suggesting a direct role for the Arg(37)-bearing region in catalysis. The crystal structure of MtOGT complexed with modified DNA solved in the present study reveals details of the protein-protein and protein-DNA interactions occurring during alkylated-DNA binding, and the protein capability also to host unmodified bases inside the active site, in a fully extrahelical conformation. Our data provide the first experimental picture at the atomic level of a possible mode of assembling three adjacent MtOGT monomers on the same monoalkylated dsDNA molecule, and disclose the conformational flexibility of discrete regions of MtOGT, including the Arg(37)-bearing random coil. This peculiar structural plasticity of MtOGT could be instrumental to proper protein clustering at damaged DNA sites, as well as to protein-DNA complexes disassembling on repair.
Trvalý link: http://hdl.handle.net/11104/0267344