Biomedical subjects

D Bossemeyer

Publications and source records attributed to D Bossemeyer.

5 recordsLinked to original sources

PubMed1995

Protein kinases--structure and function.

The solution of crystal structures from half a dozen protein kinases during the last four years in different laboratories has deepened our understanding of the catalysis and regulation of this enzyme class, and given a vigorous impetus to the whole field. Due to the great degree of sequence conservation among protein kinases the informational yield with every new structure is high, as each is a representative of the enzyme family in general and most often of a subclass in particular. This review will focus on the active site structure of cAMP-dependent protein kinase (cAPK) with special regard to two new crystal structures; one of an active protein kinase CK1*, which may represent an as yet unsolved step in the kinetic pathway, and the other of the insulin receptor kinase domain, the first structure of a tyrosine kinase.

Amino Acid Sequence↗

PubMed1994

The glycine-rich sequence of protein kinases: a multifunctional element.

Evolution favours the use of glycine-rich loops for nucleotide binding in proteins. In the large family of protein kinases, the catalytic domain of which has one of the highest degrees of conservation among all known proteins, the structure of the nucleotide-binding site differs from classical folds. We are now beginning to understand the multiple functional roles of the glycine-rich sequence in protein kinases and some of the structural constraints leading to its conservation.

Amino Acid Sequence↗

PubMed1989

K+-transport protein TrkA of Escherichia coli is a peripheral membrane protein that requires other trk gene products for attachment to the cytoplasmic membrane.

The TrkA protein, which is essential for the activity of the constitutive Trk K+-uptake system of Escherichia coli, is a peripheral membrane protein. The protein was detected in immunoblots by polyclonal antibodies to sodium dodecyl sulfate-denatured TrkA protein. In extracts from wild-type cells equal amounts of TrkA were found in the membrane and soluble fractions, suggesting that membrane binding is relatively weak. When the protein was moderately overproduced it appeared mainly in the soluble fraction; stronger overproduction led to the formation of aggregates that could not be solubilized by nonionic detergents. Mutations in the three other genes implicated in Trk activity, trkE, trkG, and trkH, reduced or abolished the binding of TrkA to the membrane. These results support the model, previously based solely on genetic data, that Trk is a multisubunit complex and implicates the products of the other trk genes in the normal binding of TrkA to the complex in the cytoplasmic membrane.

Antibodies↗

PubMed1989

Specific cesium transport via the Escherichia coli Kup (TrkD) K+ uptake system.

Escherichia coli cells which contain a functional Kup (formerly TrkD) system took up Cs+ with a moderate rate and affinity. Kup is a separate K+ uptake system with relatively little discrimination in the transport of the cations K+, Rb+, and Cs+. Regardless of the presence or absence of Kup, K+-replete cells took up Cs+ primarily by a very low affinity mode, proportional to the ratio of the Cs+ and K+ concentrations in the medium.

Binding, Competitive↗

PubMed1987

Physical mapping of the K+ transport trkA gene of Escherichia coli and overproduction of the TrkA protein.

The position on the Escherichia coli chromosome of trkA, a gene coding for a membrane protein involved in K+ transport by the constitutive uptake system Trk, was determined. We observed that the gene is transcribed in a clockwise direction and that it is located at 72.4 min on the chromosome in a 1.75-kilobase NruI-EcoRV DNA fragment 1.0 kilobase upstream of rplQ. We localized an additional gene encoding a 17,000-molecular-weight protein of unknown function between the trkA and rplQ genes. A plasmid, pDB3, was constructed in which the transcription of the trkA gene was put under the control of the lambda pL promoter. pDB3-containing cells of a strain, which contained the temperature-sensitive lambda repressor cI857 in the chromosome, overproduced the 53,000-molecular-weight TrkA protein at the nonpermissive temperature to such an extent that TrkA became the major cell protein. From cell fractionation studies, we conclude that the overproduced TrkA protein forms aggregates.

Bacterial Proteins↗