XENOPUS POLY(A) BINDING-PROTEIN - FUNCTIONAL DOMAINS IN RNA-BINDING AND PROTEIN-PROTEIN INTERACTION

Authors
Citation
U. Kuhn et T. Pieler, XENOPUS POLY(A) BINDING-PROTEIN - FUNCTIONAL DOMAINS IN RNA-BINDING AND PROTEIN-PROTEIN INTERACTION, Journal of Molecular Biology, 256(1), 1996, pp. 20-30
Citations number
27
Categorie Soggetti
Biology
ISSN journal
00222836
Volume
256
Issue
1
Year of publication
1996
Pages
20 - 30
Database
ISI
SICI code
0022-2836(1996)256:1<20:XPB-FD>2.0.ZU;2-K
Abstract
Subsets of the four RNA binding domains (RBD 1 to 4) in the Xenopus po ly-adenylate binding protein (PABP) have distinct affinities and speci ficities for RNA. RBDs 1 plus 2 exhibit RNA affinity and selectivity e qual to the wild-type (WT) protein. RBDs 3 plus 4 have distinct select ivity and about ten-fold reduced affinity for A(23), and the isolated RBDs 2 or 3 or 4 exhibit about 100-fold reduced affinity for A(23) in comparison to WT. For the full-length protein, independent RNA contact s have been mapped by UV crosslinking with RBDs 1/2 and RBDs 3/4. The carboxy-terminal, non-RBD portion of the protein does not contribute t o RNA affinity or selectivity, but confers homodimerization activity o n PABP. RBDs 3 and 4 cooperate with the C terminus to gain poly(A) org anizing activity, i.e. the ability to form an RNP with multiple, regul arly spaced copies of PABP on a poly(A) substrate. (C) 1996 Academic P ress Limited.