Open AccessApparent growth phase‐dependent phosphorylation of malonyl coenzyme A:acyl carrier protein transacylase (MCAT), a major fatty acid synthase II component in Mycobacterium bovis BCG
Author(s) -
Sinha Indrajit,
Boon Calvin,
Dick Thomas
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00664-5
Subject(s) - biochemistry , threonine , phosphorylation , biology , mycobacterium bovis , microbiology and biotechnology , protein phosphorylation , dusp6 , phosphatase , chemistry , protein kinase a , mycobacterium tuberculosis , serine , protein phosphatase 2 , medicine , tuberculosis , pathology
Probing protein extracts from exponentially growing and stationary phase cultures of Mycobacterium bovis BCG with anti‐phospho amino acid antibodies revealed a 31‐kDa anti‐phospho threonine antibody‐reactive protein specific to growing culture. The corresponding protein was purified via two‐dimensional gel electrophoresis and identified via mass spectrometry to be malonyl coenzyme A:acyl carrier protein transacylase (MCAT), a component of the fatty acid biosynthetic pathway. MCAT tagged with histidine reacted with anti‐phospho threonine antibody and was positive in an in‐gel chemical assay for phospho proteins. Analysis of the growth phase dependence of MCAT‐His phosphorylation and protein levels showed that phosphorylated MCAT‐His can be detected only in growing culture. In contrast, MCAT‐His protein level was growth phase‐independent. These results suggest that MCAT may be a substrate of a protein kinase and phosphatase, and that aspects of fatty acid synthesis in tubercle bacilli are regulated by protein phosphorylation.