1rga
From Proteopedia
| |||||||
| , resolution 1.7Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , | ||||||
| Activity: | Ribonuclease T(1), with EC number 3.1.27.3 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF RNASE T1 WITH 3'-GMP AND GUANOSINE: A PRODUCT COMPLEX
Overview
A modified method for the synthesis and separation of endo and exo guanosine 2',3'-cyclophosphorothioate (cGPS) has been developed. The exo diastereoisomer has been co-crystallized with RNase T1. cGPS is known to be a RNase T1 inhibitor but is also a very slow substrate. It was hydrolyzed during the crystallization, leaving 3'-guanylic acid (3'-GMP) in the active site. As a guanosine was also found to be bound in a subsite, the enzyme contains the products of the reaction of guanylyl-3',5'-guanosine. The structure was refined to a resolution of 1.7 A and yielded a final R value of 14.5%. In contrast to previous 3'-GMP complexes of RNase T1, the ribose phosphate moiety of the inhibitor is in contact with all the active site residues. The phosphate forms hydrogen bonds with Asn36, Tyr38, Arg77, His92, and with Asn49 from a symmetry-related molecule. The ribose 2'-OH is hydrogen-bonded to both Glu58 and His40. The interactions in the active site of the present structure are compared to those found in the 2'-GMP complex of RNase T1.
About this Structure
1RGA is a Single protein structure of sequence from Aspergillus oryzae. Full crystallographic information is available from OCA.
Reference
Crystal structure of RNase T1 with 3'-guanylic acid and guanosine., Zegers I, Haikal AF, Palmer R, Wyns L, J Biol Chem. 1994 Jan 7;269(1):127-33. PMID:8276784
Page seeded by OCA on Sun Mar 30 23:27:44 2008
