title: Characterization of a dual-active enzyme, DcpA, involved in cyclic diguanosine monophosphate turnover in Mycobacterium smegmatis.
abstract: We have reported previously that the long-term survival of Mycobacterium smegmatis is facilitated by a dual-active enzyme MSDGC-1 (renamed DcpA), which controls the cellular turnover of cyclic diguanosine monophosphate (c-di-GMP). Most mycobacterial species possess at least a single copy of a DcpA orthologue that is highly conserved in terms of sequence similarity and domain architecture. Here, we show that DcpA exists in monomeric and dimeric forms. The dimerization of DcpA is due to non-covalent interactions between two protomers that are arranged in a parallel orientation. The dimer shows both synthesis and hydrolysis activities, whereas the monomer shows only hydrolysis activity. In addition, we have shown that DcpA is associated with the cytoplasmic membrane and exhibits heterogeneous cellular localization with a predominance at the cell poles. Finally, we have also shown that DcpA is involved in the change in cell length and colony morphology of M. smegmatis. Taken together, our study provides additional evidence about the role of the bifunctional protein involved in c-di-GMP signalling in M. smegmatis.
authors.affiliation: Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Indra Mani
authors.initials: IM
authors.lastname: Sharma
authors.affiliation: Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Sunita
authors.initials: S
authors.lastname: Prakash
authors.affiliation: Institute for Research in Immunology and Cancer, Université de Montréal, Montréal H3C 3J7, Québec, Canada.
authors.forename: Thillaivillalan
authors.initials: T
authors.lastname: Dhanaraman
authors.affiliation: Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Chatterji
mesh_terms: D002462:Cell Membrane / Q000201:enzymology; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism*; D006868:Hydrolysis; D020102:Mycobacterium smegmatis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D019761:Phosphorus-Oxygen Lyases / Q000378:metabolism*; D011485:Protein Binding; D055503:Protein Multimerization
chemical_list: D029968:Escherichia coli Proteins; C062025:bis(3',5')-cyclic diguanylic acid; D019761:Phosphorus-Oxygen Lyases; C060720:diguanylate cyclase; D006152:Cyclic GMP