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Plasticity, ligand conformation and enzyme action of Mycobacterium smegmatis MutT1
Author(s) -
Raj Prateek,
Karthik S.,
Arif S. M.,
Varshney U.,
Vijayan M.
Publication year - 2020
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.374
H-Index - 138
ISSN - 2059-7983
DOI - 10.1107/s2059798320010992
Subject(s) - mycobacterium smegmatis , hydrolase , chemistry , stereochemistry , enzyme , ligand (biochemistry) , crystallography , intermolecular force , biophysics , biochemistry , molecule , biology , receptor , mycobacterium tuberculosis , medicine , tuberculosis , pathology , organic chemistry
Mycobacterium smegmatis MutT1 ( Ms MutT1) is a sanitation enzyme made up of an N‐terminal Nudix hydrolase domain and a C‐terminal domain resembling a histidine phosphatase. It has been established that the action of MutT1 on 8‐oxo‐dGTP, 8‐oxo‐GTP and diadenosine polyphosphates is modulated by intermolecular interactions. In order to further explore this and to elucidate the structural basis of its differential action on 8‐oxo‐NTPs and unsubstituted NTPs, the crystal structures of complexes of Ms MutT1 with 8‐oxo‐dGTP, GMPPNP and GMPPCP have been determined. Replacement soaking was used in order to ensure that the complexes were isomorphous to one another. Analysis of the structural data led to the elucidation of a relationship between the arrangements of molecules observed in the crystals, molecular plasticity and the action of the enzyme on nucleotides. The dominant mode of arrangement involving a head‐to‐tail sequence predominantly leads to the generation of NDPs. The other mode of packing arrangement appears to preferentially generate NMPs. This work also provides interesting insights into the dependence of enzyme action on the conformation of the ligand. The possibility of modulating the enzyme action through differences in intermolecular interactions and ligand conformations makes Ms MutT1 a versatile enzyme.