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D R Gill

Publications and source records attributed to D R Gill.

58 records · Page 4Linked to original sources

A new cell division operon in Escherichia coli.

At 76 min on the E. coli genetic map there is a cluster of genes affecting essential cellular functions, including the heat shock response and cell division. A combination of in-vivo and in-vitro genetic analysis of cell division mutants suggests that the cell division gene fts E is the second gene in a 3 gene operon. A cold-sensitive mutant, defective in the third gene, is also unable to divide at the restrictive temperature, and we designate this new cell division gene fts X. Another cell division gene, fts S, is very close to, but distinct from, the 3 genes of the operon. The fts E product is a 24.5 Kd polypeptide which shows strong homology with a small group of proteins involved in transport. Both the fts E product and the protein coded by the first gene (fts Y) in the operon have a sequence motif found in a wide range of heterogeneous proteins, including the Ras proteins of yeast. This common domain is indicative of a nucleotide-binding site.

Amino Acid Sequence↗

Response of fall-born calves to progesterone-estradiol benzoate implants and reimplants.

Two trials, involving 469 steer and heifer calves, were conducted to evaluate the practices of implanting or reimplanting suckling fall-born calves with progesterone-estradiol benzoate (PE) implants (100 mg of progesterone, 10 mg of estradiol benzoate). Calves having an average initial weight of 67 kg were randomly allocated within sex and location to remain either nonimplanted or to receive a PE implant in the late fall, in the spring just before green grass, or in both fall and spring. All animals grazed good- to excellent-quality native Bluestem range. Nonimplanted calves in Trial 1 gained .57 kg/d during the winter months and PE implants improved growth rate by 7% to .61 kg/d (P less than .05). Growth rate of calves on dry winter range in Trial 2 was only .20 kg/d, and was not affected by PE implants. Average daily gain of nonimplanted calves during the spring and summer months was .96 and .87 kg/d for trials 1 and 2, respectively. Performance of implanted calves during that period was improved an average of 4.3 to 10% (P less than .05) by PE implants in both trials regardless of when the calves were implanted. Growth rate of calves over the entire 8-mo trials was .66 kg/d for nonimplanted calves and was improved (P less than .01) to .70, .70 and .71 kg/d for calves on the two single-implant and reimplant schedules, respectively. Implanted calves gained an average of 10.4 kg more than nonimplanted calves during the study.

Analysis of Variance↗

A family of related ATP-binding subunits coupled to many distinct biological processes in bacteria.

Many biological processes are coupled to ATP hydrolysis. We describe here a class of closely related ATP-binding proteins, from several bacterial species, which are associated with a variety of cellular functions including membrane transport, cell division, nodulation in Rhizobium and haemolysin export. These proteins comprise a family of structurally and functionally related subunits which share a common evolutionary origin, bind ATP and probably serve to couple ATP hydrolysis to each of these biological processes. This finding suggests a specific role for ATP in cell division, nodulation during nitrogen fixation and protein export, and allows us to assign a probable function to one of the protein components from each of these systems.

Adenosine Triphosphate↗