25 research outputs found
Domainal evolution of a prokaryotic DNA repair protein and its relationship to active-transport proteins
Regulation of the phosphate regulon of Escherichia coli: Characterization of the promoter of the pstS gene
Molecular Genetics of Bacterial Polyphosphate Accumulation to Better Understand the Mechanism Underlying Biological Phosphorus Removal
A family of related ATP-binding subunits coupled to many distinct biological processes in bacteria
The Escherichia coli cell division proteins FtsY, FtsE and FtsX are inner membrane-associated
Effect of mutations in the −10 region of the phoE promoter in Escherichia coli on regulation of gene expression
Extreme arsenic resistance by the acidophilic archaeon 'Ferroplasma acidarmanus' Fer1
‘Ferroplasma acidarmanus’ Fer1 is an arsenic-hypertolerant acidophilic archaeon isolated from the Iron Mountain mine, California; a site characterized by heavy metals contamination. The presence of up to 10 g arsenate per litre [As(V); 133 mM] did not significantly reduce growth yields, whereas between 5 and 10 g arsenite per litre [As(III); 67–133 mM] significantly reduced the yield. Previous bioinformatic analysis indicates that ‘F. acidarmanus’ Fer1 has only two predicted genes involved in arsenic resistance and lacks a recognizable gene for an arsenate reductase. Biochemical analysis suggests that ‘F. acidarmanus’ Fer1 does not reduce arsenate indicating that ‘F. acidarmanus’ Fer1 has an alternative resistance mechanism to arsenate other than reduction to arsenite and efflux. Primer extension analysis of the putative ars transcriptional regulator (arsR) and efflux pump (arsB) demonstrated that these genes are co-transcribed, and expressed in response to arsenite, but not arsenate. Two-dimensional polyacrylamide gel electrophoresis analysis of ‘F. acidarmanus’ Fer1 cells exposed to arsenite revealed enhanced expression of proteins associated with protein refolding, including the thermosome Group II HSP60 family chaperonin and HSP70 DnaK type heat shock proteins. This report represents the first molecular and proteomic study of arsenic resistance in an acidophilic archaeon