2c8l

From Proteopedia

Revision as of 14:56, 30 October 2007

CRYSTAL STRUCTURE OF (SR) CALCIUM-ATPASE E2(TG) FORM

Overview

We present crystal structures of the calcium-free E2 state of the, sarcoplasmic reticulum Ca2+ -ATPase, stabilized by the inhibitor, thapsigargin and the ATP analog AMPPCP. The structures allow us to, describe the ATP binding site in a modulatory mode uncoupled from the, Asp351 phosphorylation site. The Glu439 side chain interacts with AMPPCP, via an Mg2+ ion in accordance with previous Fe2+ -cleavage studies, implicating this residue in the ATPase cycle and in magnesium binding., Functional data on Ca2+ mediated activation indicate that the crystallized, state represents an initial stage of ATP modulated deprotonation of E2, preceding the binding of Ca2+ ions in the membrane from the cytoplasmic, side. We propose a mechanism of Ca2+ activation of phosphorylation leading, directly from ... [(full description)]

About this Structure

2C8L is a [Single protein] structure of sequence from [Oryctolagus cuniculus] with NA and TG1 as [ligands]. Active as [Calcium-transporting ATPase], with EC number [3.6.3.8]. Structure known Active Site: AC1. Full crystallographic information is available from [OCA].

Reference

Modulatory and catalytic modes of ATP binding by the calcium pump., Jensen AM, Sorensen TL, Olesen C, Moller JV, Nissen P, EMBO J. 2006 Jun 7;25(11):2305-14. Epub 2006 May 18. PMID:16710301

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