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Expression of Functional Streptomyces coelicolor H+-Pyrophosphatase and Characterization of Its Molecular Properties.
- Source :
-
Journal of Biochemistry . Aug2005, Vol. 138 Issue 2, p183-191. 9p. - Publication Year :
- 2005
-
Abstract
- H+-translocating pyrophosphatases (H+-PPases) are proton pumps that are found in many organisms, including plants, bacteria and protozoa. Streptomyces coelicolor is a soil bacterium that produces several useful antibiotics. Here we investigated the properties of the H+-PPase of S. coelicolor by expressing a synthetic DNA encoding the amino-acid sequence of the H+-PPase in Escherichia coli. The H+-PPase from E. coli membranes was active at a relatively high pH, stable up to 50°C, and sensitive to N-ethylmaleimide, N,N′-dicyclohexylcarbodiimide and acylspermidine. Enzyme activity increased by 60% in the presence of 120 mM K+, which was less than the stimulation observed with plant vacuolar H+-PPases (type I). Substitutions of Lys-507 in the Gly-Gln-x-x-(Ala/Lys)-Ala motif, which is thought to determine the K+ requirement of H+-PPases, did not alter its K+ dependence, suggesting that other residues control this feature of the S. coelicolor enzyme. The H+-PPase was detected during early growth and was present mainly on the plasma membrane and to a lesser extent on intracellular membranous structures. [ABSTRACT FROM PUBLISHER]
Details
- Language :
- English
- ISSN :
- 0021924X
- Volume :
- 138
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Journal of Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 44543702
- Full Text :
- https://doi.org/10.1093/jb/mvi112