Many proteins have recently been shown to localize to different regions of the bacterial cell. This is most striking in the case of the Escherichia coli chemotaxis pathway in which the components localize at the cell poles. Rhodobacter sphaeroides has a more complex chemotaxis system with two complete pathways, each localizing to different positions, one pathway at the pole and one at a discrete cluster within the cytoplasm of the bacterium.
View Article and Find Full Text PDFAgeing is linked to the accumulation of replicatively senescent cells. The best model system to date for studying human cellular ageing is the progeroid Werner's syndrome (WS), caused by a defect in WRN, a recQ-like helicase that also possesses exonuclease activity. In this paper, we characterise the interaction between WRN and an essential replication factor, PCNA.
View Article and Find Full Text PDFProliferating cell nuclear antigen seems to exist as a single form in higher eukaryotic cells and plays multiple roles in nucleic acid metabolism. We have identified a second additional proliferating cell nuclear antigen (PfPCNA2) in Plasmodium falciparum on the basis of several lines of evidence. (1) PfPCNA2, consisting of 264 amino acid residues with a predicted molecular mass of 30.
View Article and Find Full Text PDFThe purple photosynthetic bacterium Rhodobacter sphaeroides has three loci encoding multiple homologues of the bacterial chemosensory proteins: 13 putative chemoreceptors, four CheW, four CheA, six CheY, two CheB and three CheR. Previously, studies have shown that, although deletion of cheOp1 led to only minor changes in behaviour, deletion of cheOp2 led to a loss of taxis. The third locus encodes two CheA, one CheR, one CheB, one CheW, one CheY, a putative cytoplasmic chemoreceptor (TlpT) and a protein showing homology to the chromosomal partitioning factor Soj (designated Slp).
View Article and Find Full Text PDF