Xi Chen, Jianwen Fang, Jianbo Zhang, Ziye Liu, Jun Shao, Przemyslaw Kowal, Peter Andreana, and Peng George Wang* Department of Chemistry, Wayne State UniVersity Detroit, Michigan 48202 ReceiVed October 27, 2000 Application of carbohydrates in modern medicine is limited by the high cost of synthesis of most biologically important glycoconjugates. It is generally recognized that glycosyltransfera...

Protein L is a bacterial surface protein with 4-5 immunoglobulin (Ig)-binding domains (B1B5), each of which appears to have two binding sites for Ig, corresponding to the two edges of its â-sheet. To verify these sites biochemically and to probe their relative contributions to the protein L-Ig κ light chain (κ) interaction, we compared the binding of PLW (the Y47W mutant of the B1 domain) to th...

Regulator of G protein signaling (RGS) proteins are a family of approximately 20 proteins that negatively regulate signaling through heterotrimeric G protein-coupled receptors. The RGS proteins act as GTPase-activating proteins (GAPs) for certain Ga subunits and as effector antagonists for Gqa. Mouse RGS14 encodes a 547-amino-acid protein with an N-terminal RGS domain, which is highly expressed...

Arabidopsis COP1 acts inside the nucleus to suppress photomorphogenic cellular development, and light inactivation of COP1 may involve a specific control of its nuclear activity in hypocotyls and cotyledons, but not in roots, of developing seedlings. To understand the molecular mechanisms ofCOP1 action during light-mediated development, we initiated a screen for Arabidopsis cDNAs encoding prote...

Ribonucleases play an important role in RNA metabolism. Yet, they are also potentially destructive enzymes whose activity must be controlled. We describe here a novel regulatory mechanism affecting RNase R, a 3' to 5' exoribonuclease able to act on essentially all RNAs including those with extensive secondary structure. Most RNase R is sequestered on ribosomes in growing cells where it is stabl...

Many Regulators of G protein Signaling (RGS) proteins accelerate the intrinsic GTPase activity of Gia and Gqa-subunits [i.e., behave as GTPase-activating proteins (GAPs)] and several act as Gqa-effector antagonists. RGS3, a structurally distinct RGS member with a unique N-terminal domain and a C-terminal RGS domain, and an N-terminally truncated version of RGS3 (RGS3CT) both stimulated the GTPa...