Eukaryotic-type serine/threonine kinase mediated phosphorylation at Thr¹⁶⁹ perturbs mycobacterial guanylate kinase activity.

ABSTRACT: Guanylate kinase is an essential and conserved enzyme in nucleotide biosynthetic pathway that transfers phosphoryl group of ATP to GMP for yielding GDP. Here, we report the phosphorylation of guanylate kinase from Mycobacterium tuberculosis (mGmk) by eukaryotic-type Ser/Thr kinase, PknA. Mass spectrometric studies identified Thr¹⁰¹ and Thr¹⁶⁹ as phosphorylatable residues in mGmk. To evaluate the significance of phosphorylation in these threonines, two point (T101A and T169A) and one double (T101A-T169A) mutants were generated. The kinase assay with these mutant proteins revealed the major contribution of Thr¹⁶⁹ compared with Thr¹⁰¹ in the phosphorylation of mGmk. Kinetic analysis indicated that p-mGmk was deficient in its enzymatic activit

SUBMITTER: S Yadav G 

PROVIDER: S-EPMC5686395 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature