N Binns | PubMed Health

PubMed1993

PcnB is required for the rapid degradation of RNAI, the antisense RNA that controls the copy number of ColE1-related plasmids.

The replication of ColE1-related plasmids is controlled by an unstable antisense RNA, RNAI, which can interfere with the successful processing of the RNAII primer of replication. We show here that a host protein, PcnB, supports replication by promoting the decay of RNAI. In bacterial strains deleted for PcnB a stable, active form of RNAI, RNAI*, which appears to be identical to the product of 5'-end processing by RNAase E, accumulates. This leads to a reduction in plasmid copy number. We show, using a GST-PcnB fusion protein, that PcnB does not interfere with RNAI/RNAII binding in vitro. The fusion protein, like PcnB, has polyadenylating activity and is able to polyadenylate RNAI (and also another antisense RNA, CopA) in vitro.

Ampicillin Resistance↗

PubMed1987

Blood lactate changes during exercise at high altitude.

Blood lactate concentrations were measured in 18 normal subjects at the end of an exercise test designed to maintain heart rate at 85% of maximum for 15 minutes. Blood lactate concentrations were reduced at high altitude (4846 m) and correlated positively with basal pH and negatively with basal Pa,O2 levels. Blood lactate concentrations tended to be lower in those subjects on acetazolamide but were not correlated with the severity of acute mountain sickness or with the workload of the exercise test. We conclude that the pH changes are probably the most significant factor in reducing lactate concentrations.

Acetazolamide↗