A putative proton binding site of plasma membrane H+‐ATPase identified through homology modelling

FEBS Letters

Palmgren, Michael G.¹  Bukrinsky, Jens T.²  Larsen, Sine²  Buch-Pedersen, Morten J.¹ 

[1] Department of Plant Biology, The Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark;Centre for Crystallographic Studies, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark

关键词: Auto-inhibition;    H+-ATPase;    Hydronium ion;    Proton binding site;    Regulatory domain;    Rabbit sarcoplasmic reticulum Ca2+-ATPase isoform 1;    Proton pump;    A-domain;    actuator or anchor domain;    ACA2;    Arabidopsis thaliana auto-inhibited Ca2+-ATPase isoform 2;    AHA2;    Arabidopsis thaliana PM H+-ATPase isoform 2;    M1–M10;    transmembrane segments 1–10;    N-domain;    nucleotide binding domain;    P-domain;    phosphorylation domain;    PM;    plasma membrane;    PMA1;    Saccharomyces cerevisiae PM H+-ATPase isoform 1;    PMA2;    Nicotiana plumbaginifolia PM H+-ATPase isoform 2;    R-domain;    C-terminal regulatory domain;    SERCA1a;    rabbit SR Ca2+-ATPase isoform 1a;    SR;    sarcoplasmic reticulum;   

DOI  :  10.1016/S0014-5793(01)02301-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have used the 2.6 Å structure of the rabbit sarcoplasmic reticulum Ca²⁺-ATPase isoform 1a, SERCA1a [Toyoshima, C., Nakasako, M., Nomura, H. and Ogawa, H. (2000) Nature 405, 647–655], to build models by homology modelling of two plasma membrane (PM) H⁺-ATPases, Arabidopsis thaliana AHA2 and Saccharomyces cerevisiae PMA1. We propose that in both yeast and plant PM H⁺-ATPases a strictly conserved aspartate in transmembrane segment (M)6 (D684_AHA2/D730_PMA1), and three backbone carbonyls in M4 (I282_AHA2/I331_PMA1, G283_AHA2/I332_PMA1 and I285_AHA2/V334_PMA1) comprise a binding site for H₃O⁺, suggesting a previously unknown mechanism for transport of protons. Comparison with the structure of the SERCA1a made it feasible to suggest a possible receptor region for the C-terminal auto-inhibitory domain extending from the phosphorylation and anchor domains into the transmembrane region.

【 授权许可】

Unknown