1uq5

From Proteopedia

Revision as of 14:03, 30 October 2007

RICIN A-CHAIN (RECOMBINANT) N122A MUTANT

Overview

Models for the binding of the sarcin-ricin loop (SRL) of 28S ribosomal RNA, to ricin A chain (RTA) suggest that several surface exposed arginine, residues surrounding the active site cleft make important interactions, with the RNA substrate. The data presented in this study suggest differing, roles for these arginyl residues. Substitution of Arg48 or Arg213 with Ala, lowered the activity of RTA 10-fold. Furthermore, substitution of Arg213, with Asp lowered the activity of RTA 100-fold. The crystal structure of, this RTA variant showed it to have an unaltered tertiary structure, suggesting that the positively charged state of Arg213 is crucial for, activity. Substitution of Arg258 with Ala had no effect on activity, although substitution with Asp lowered activity 10-fold. Substitution of, ... [(full description)]

About this Structure

1UQ5 is a [Single protein] structure of sequence from [Ricinus communis] with ACT and SO4 as [ligands]. Active as [rRNA N-glycosylase], with EC number [3.2.2.22]. Structure known Active Site: AC1. Full crystallographic information is available from [OCA].

Reference

The effect of mutations surrounding and within the active site on the catalytic activity of ricin A chain., Marsden CJ, Fulop V, Day PJ, Lord JM, Eur J Biochem. 2004 Jan;271(1):153-62. PMID:14686928

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