type	Journal Article
authors	Forchhammer, K.; Boesmiller, K.; Bock, A.
title	The function of selenocysteine synthase and SELB in the synthesis and incorporation of selenocysteine
journal	Biochimie
Activity	2.9.1.1
ui	92215847
year	(1991)
volume	73
number	12
pages	1481-6.
keywords	Bacterial Proteins/*metabolism
abstract	The selAB operon codes for the proteins selenocysteine synthase and SELB which catalyse the synthesis and cotranslational insertion of selenocysteine into protein. This communication deals with the biochemical characterisation of these proteins and in particular with their specific interaction with the selenocysteine-incorporating tRNA(Sec). Selenocysteine synthase catalyses the synthesis of selenocysteyl-tRNA(Sec) from seryl-tRNA(Sec) in a pyridoxal phosphate- dependent reaction mechanism. The enzyme specifically recognizes the tRNA(Sec) molecule; a cooperative interaction between the tRNA binding site and the catalytically active pyridoxal phosphate site is suggested. SELB is an EF-Tu-like protein which specifically complexes selenocysteyl-tRNA(Sec). Interaction with the selenol group of the side chain of the aminoacylated residue is a prerequisite for the formation of a stable SELB.tRNA complex. Mechanistically, this provides the biochemical basis for the exclusive selection of selenocysteyl- tRNA(Sec) in the decoding step of a selenocysteine-specific UGA triplet.
last changed	2002/11/12 16:17