7. BACTERIOLOGY

摘要

1175. The many levels of control on bacterial selenoprotein synthesis - Yoshizawa S. and Bock A. [A. Bock, Department of Biology I, Microbiology, University of Munich, Munich, Germany] - BIO-CHIM. BIOPHYS. ACTA GEN. SUBJ. 2009 1790/11 (1404-1414) -summ in ENGLrnSelenium shares many chemical facets with sulphur but differs from it in the redox potential, especially of the Se~(2-)/S~(2-) oxidation state. The higher chemical reactivity of the deprotonated selenol has been used by Biology in the synthesis of the amino acid selenocys-teine and its DNA-encoded incorporation into specific positions of proteins to enhance their structural role or their activity. Since selenocysteine is a steric isomer of cysteine, numerous control mechanisms have been developed which prevent cross-intrusion of the elements during biosynthesis and insertion. As described in this review, these fidelity steps occur at the genetic, biochemical and physiological level.