at Related Biological Terms

As applied to enzymes, the regulation of activity by modifications that may be reversible (e.g. phosphorylation or adenylation) or irreversible (e.g. limited proteolysis). (see also post-transcriptional modification; post-translational modification)

The minimum concentration of a detergent at which it will form micelles and below which it is a true solution.

A protein product resulting from mutation that has lost its function but is recognizable by its ability to react with antibodies raised against the normal protein. More broadly, material may cross-react because it bears an epitope in common with the antigen.

control of a metabolic pathway by the product of a different but related pathway, e.g. activation of the reduction of ADP to dADP by dGTP.

Essentially identical to the selected and amplified (protein) binding site oligonucleotide (SAAB) and target detection assay (TDA) procedures; a procedure for identification of consensus sequences of DNA to which a protein, e.g. a transcription factor, may bind. A random polynucleotide sequence is synthesized flanked by two defined sequences that will serve as templates for PCR primers; the polynucleotides are exposed to the DNA-binding protein, any complex that is formed is separated from the unliganded polynucleotides (e.g. by gel shift assay, affinity chromatography, filter binding) and the polynucleotide of the complex is isolated and amplified by PCR; repeated recycling through the sequence of ligand formation, selection and amplification results in a preparation that is sufficiently pure to be cloned into bacteria for larger-scale production. A variant is systematic evolution of ligands by exponential enrichment (SELEX) for identification of RNA sequences, which begins with a mixture of polyribonucleotides and in each cycle produces DNA from the selected RNA-protein complex using reverse transcriptase, amplifies it by PCR, and then produces new RNA transcripts for the next round of selection. CASTing: Wright, W.E. and Funk, W.D. (1993) Trends Biochem. Sci. 18, 77-80; SAAB: Blackwell, T.K. and Weintraub, H.W. (1990) Science 250, 1104-1110; SELEX: Turek, C. and Gold, L. (1990) Science 249, 505-510; TDA: Thiesen, H.-J. and Bach, C. (1990) Nucleic Acids Res. 18, 3203-3209; Ouellette, M.M. and Wright, W.E. (1995) Curr. Opin. Biotechnol. 6, 65-72

A term applied both to the superfamily of cysteine proteinase inhibitors and to one subgroup; the other subgroups are the kininogens and stefins.

A phenomenon that represses expression of regions of the genome. Transcription is prevented when the DNA is methylated and folded into nucleosomes. Eukaryotic DNA is methylated almost exclusively as 5-methyl cytosine; prokaryotic DNA is methylated also as 6-methyl adenosine. (see also imprinting)Kass, S.U., Landsberger, N. and Wolffe, A.P. (1997) Curr. Biol. 7, 157-165

(= pentose phosphate pathway)

The abstraction of the elements of ammonia from a compound, e.g. from histidine by the histidine lyase reaction, or from AMP in the adenylate deaminase reaction.

A sequence of a death-associated protein or its gene, which is common to several death-associated proteins.