at Related Biological Terms

Such a mutation results in an amino acid substitution that preserves an essential chemical characteristic of the original, e.g. a leucine for an isoleucine, an aspartate for a glutamate, a lysine for an arginine.

The inversion or excision of a DNA sequence or the integration of a foreign DNA sequence into a homologous genomic site. These all require homologous recombination at the sites of inversion, excision or integration, and contrast with transposition, in which a DNA sequence is inserted or removed from a non-homologous site by excision of the donor sequence from its source, cutting open the acceptor site, and insertion of the transposed sequence and its ligation in place.Polard, P. and Chandler, M. (1995) Mol. Microbiol. 15, 13-23 Recommended reading: next generation sequencing

The attachment to a protein and modification of N-linked carbohydrate moieties that occurs in the endoplasmic reticulum (see also terminal glycosylation)

A two-dimensional nuclear magnetic resonance technique for detection of connectivity of the resonance of two centres through the covalent bonds that join them. (see also nuclear Overhauser and exchange spectroscopy (NOESY))Kay, L.E. (1995) Curr. Opin. Struct. Biol. 5, 674-681

In electron spin resonance and nuclear magnetic resonance spectroscopy, a time constant for the interaction of an observed species with its environment, often related to the rate of decay of its observed property; affected by spin relaxation, rotational motion and chemical exchange.

A variant of partition chromatography that does not use a solid support to stabilize the stationary phase. A horizontal helical tube is filled with the stationary phase which has been equilibrated with the mobile phase; the mobile phase with solutes to be separated is introduced into one end of the helical tube and fractions are collected from the other. Equilibrium between the phases may be enhanced by slow rotation of the tube around its axis.

(= centrifugal elutriation)

The synthesis of the phosphate anhydride bonds of ATP using energy derived from the electron transport chain.

(see entropy effect)

A stage in some enzymic reactions in which one moiety of a substrate is attached by a covalent bond to the enzyme.