Adenylate kinase complements nucleoside diphosphate kinase deficiency in nucleotide metabolism.

Abstract

Nucleoside diphosphate (NDP) kinase is a ubiquitous nonspecific enzyme that evidently is designed to catalyze in vivo ATP-dependent synthesis of ribo-and deoxyribonucleoside triphosphates from the corresponding diphosphates. Because Escherichia coli contains only one copy of ndk, the structural gene for this enzyme, we were surprised to find that ndk disruption yields bacteria that are still viable. These mutant cells contain a protein with a small amount NDP kinase activity. The Cells. Cell extracts obtained by sonication from a 2-ml overnight culture of strain QL7623 were incubated at 55°C for 5 min in the sample loading buffer (80 mM Tris-HCl, pH 6.8/1% SDS/10% glycerol/4% 2-mercaptoethanol/0.005% bromophenol blue). SDS/PAGE was carried out with use of a 15% polyacrylamide gel at 4°C with constant current of 7 mA. After electrophoresis the gels were sliced into 3 mm (see Fig. 1A) or 4 mm (see Fig. 1B

Purine and pyrimidine nucleotide metabolism in Mollicutes

“…It is possible that, in the absence of a genuine NDP kinase activity, low substrate-specificity kinases could provide the necessary (d)NTPs required for normal growth and reproduction . Interestingly, adenylate kinase was identified as the enzyme responsible for the NDP kinase activity detected in Escherichia coli ndk mutants (Lu and Inouye, 1996). Later, it was found that adenylate kinase from Mycobacterium tuberculosis also has NDP kinase activity (Meena et al, 2003).…”

Intrinsic nucleoside diphosphate kinase‐like activity as a novel function of 14‐3‐3 proteins

“…The nucleotide specificity of 14-3-3 proteins was examined by incubation at 37°C for 6 h in Buffer B (100 mM HEPES-KOH, pH 8, 1 uCi of [y- 32 P]ATP, 6 mM MgCl 2 ) with 33 pmol (calculated as a monomer with a mean molecular mass of 30 kDa) of 14-3-3 and 0.5 mM concentrations of various ribo-or deoxyribo-nucleoside diphosphates as phosphate acceptors in 20 ul of reaction mixture [24]. After incubation, the nucleotides were resolved by polyethylene-imi-no-cellulose TLC in 0.75 M KH2PO4, pH 3.5, and quantified with an imaging analyzer.…”

NUCLEOSIDE DIPHOSPHATE KINASE GENE IS EXPRESSED THROUGH MULTIPLE TRANSCRIPTS IN Mycobacterium smegmatis

“…The requirement for NTPs and dNTPs, during stress conditions, might be getting mediated through the marginal modulation of the levels of T2. Nevertheless, NDK is nonessential for most bacterial systems, including M. tuberculosis [20], as other enzymes such as adenylate kinase [52] and polyphosphate kinase [53,54], which are present in M. smegmatis also (TIGR Database), might be able to synthesise NTPs and dNTPs, as in E. coli [52,53]. Therefore, M. smegmatis may not be entirely dependent on NDK modulation for NTPs and dNTPs and this may probably be the reason for the lack of significant modulation of NDK.…”