2i4k
From Proteopedia
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Solution Structure of the PX domain of Sorting Nexin 1
Overview
The sorting nexin (SNX) family of proteins is characterized by, sequence-related phox homology (PX) domains. A minority of PX domains bind, with high affinity to phosphatidylinositol 3-phosphate [PI(3)P], whereas, the majority of PX domains exhibit low affinity that is insufficient to, target them to vesicles. SNX1 is located on endosomes, but its low, affinity PX domain fails to localize in vivo. The NMR structure of the PX, domain of SNX1 reveals an overall fold that is similar to high-affinity PX, domains. However, the phosphatidylinositol (PI) binding pocket of the SNX1, PX domain is incomplete; regions of the pocket that are well defined in, high-affinity PX domains are highly mobile in SNX1. Some of this mobility, is lost upon binding PI(3)P. The C-terminal domain of SNX1 is a long, helical dimer that localizes to vesicles but not to the early endosome, antigen-1-containing vesicles where endogenous SNX1 resides. Thus, the, obligate dimerization of SNX1 that is driven by the C-terminal domain, creates a high-affinity PI binding species that properly targets the holo, protein to endosomes.
About this Structure
2I4K is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Determinants of the endosomal localization of sorting nexin 1., Zhong Q, Watson MJ, Lazar CS, Hounslow AM, Waltho JP, Gill GN, Mol Biol Cell. 2005 Apr;16(4):2049-57. Epub 2005 Jan 26. PMID:15673616
Page seeded by OCA on Mon Nov 12 22:40:55 2007
