欢迎访问西亚试剂!
西亚试剂banner
西亚试剂banner
西亚试剂banner

当前位置:首页 > 新闻中心

西亚试剂:The GTPase Cycle of the Chloroplast Import Receptors Toc33/

发布时间:2026-01-18

 

The GTPase Cycle of the Chloroplast Import Receptors Toc33/Toc34: Implications from Monomeric and Dimeric Structures
Patrick Koenig,1 Mislav Oreb,2,4 Anja Höfle,2,4 Sabine Kaltofen,3 Karsten Rippe,3 Irmgard Sinning,1 Enrico Schleiff,2,4 and Ivo Tews1,

Summary

Transport of precursor proteins across chloroplast membranes involves the GTPases Toc33/34 and Toc159 at the outer chloroplast envelope. The small GTPase Toc33/34 can homodimerize, but the regulation of this interaction has remained elusive. We show that dimerization is independent of nucleotide loading state, based on crystal structures of dimeric Pisum sativum Toc34 and monomeric Arabidopsis thaliana Toc33. An arginine residue is—in the dimer—positioned to resemble a GAP arginine finger. However, GTPase activation by dimerization is sparse and active site features do not explain catalysis, suggesting that the homodimer requires an additional factor as coGAP. Access to the catalytic center and an unusual switch I movement in the dimeric structure support this finding. Potential binding sites for interactions within the Toc translocon or with precursor proteins can be derived from the structures.

 

 

上一篇:阿魏酸护肤功效
下一篇:西亚试剂:3,3'-硫代二丙酸
版权所有:山东西亚化学有限公司

鲁ICP备20015914号-4