A novel regulatory motif at the hinge dimer interface of the MksB mediates dimerization and DNA binding activity.

Autor: Kumari P; Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, Karnataka, 570020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India., Hegde V; Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, Karnataka, 570020, India., Bakshi A; Department of Food Safety and Analytical Quality Control Laboratory, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, Karnataka, 570020, India., Suguna M; Prosetta Bioconformatics Private Limited, #67B, Hootagalli, Karnataka, 570018, India., Prasad MD; Prosetta Bioconformatics Private Limited, #67B, Hootagalli, Karnataka, 570018, India., Gnanesh Kumar BS; Department of Biochemistry, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, Karnataka, 570020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India., Usharani D; Department of Food Safety and Analytical Quality Control Laboratory, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, Karnataka, 570020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India., Sharan K; Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, Karnataka, 570020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India., Kumar R; Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, Karnataka, 570020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India; School of Biotechnology, Jawaharlal Nehru University, New Delhi, India. Electronic address: ravikr@jnu.ac.in.
Jazyk: angličtina
Zdroj: Biochimie [Biochimie] 2024 Nov 14. Date of Electronic Publication: 2024 Nov 14.
DOI: 10.1016/j.biochi.2024.11.005
Abstrakt: The Structural Maintenance of Chromosome (SMC) protein is essential for various cellular processes, including chromosome organization, DNA repair, and genome stability. MksB, an alternative SMC protein present in prokaryotes, comprises a hinge dimerization domain and an ABC ATPase head domain linked by a coiled-coil arm. While hinge dimerization in bacterial and eukaryotic SMCs is attributed to conserved glycines, our study unveils the critical role of a novel KDDR motif located at a loop near the hinge dimer interface in Mycobacterium smegmatis MksB (MsMksB). We demonstrate the regulatory role of this motif in MsMksB dimerization and DNA binding activity. The K600D mutation in the KDDR motif induces MsMksB dimer-to-monomer conversion, highlighting the significance of this motif in MsMksB dimerization. Mass spectrometry-based mapping of the DNA binding site revealed the lysine's involvement in protein-DNA interaction. Monomers of the hinge domain lose DNA binding activity, and MsMksB single-arm mutants exhibit reduced DNA binding and ATPase activity, underscoring the importance of hinge-mediated dimerization in MsMksB function. Notably, the R603D mutant retains dimerization but shows compromised ATPase and DNA binding activities. Mutants with defective ATPase activity exhibit impaired DNA condensation in vivo. These findings provide novel regulatory insight into the mechanism of MksB dimerization and DNA binding, uncovering the fundamental processes of chromosome condensation and segregation.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)
Databáze: MEDLINE
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