1FWQ: SOLUTION STRUCTURE OF HUMAN MSS4, A GUANINE NUCLEOTIDE EXCHANGE FACTOR FOR RAB PROTEINS

Citation:
Abstract
Guanine-nucleotide-exchange factors (GEFs) promote the exchange of GDP for GTP in Ras GTPases, and thereby positively regulate their functions. Members of the Sec4/Ypt1/Rab branch of the Ras superfamily are essential for vesicular transport. A GEF for a subset of Rab proteins, termed mammalian suppressor of Sec4 (Mss4), has been identified. Here we use multidimensional NMR to determine the structure of human Mss4 (hMss4), which is the first tertiary structure established for a protein with GEF activity. Mss4 contains a central beta-sheet sandwiched between two small sheets. It also binds a Zn2+ ion through Cys 23, Cys 26, Cys 94 and Cys 97. The Rab-binding surface of hMss4 has subsequently been delineated using chemical-shift perturbation experiments and site-directed mutagenesis. The active site of hMss4 involves the Zn(2+)-binding region and a neighbouring loop.
PDB ID: 1FWQDownload
MMDB ID: 14280
PDB Deposition Date: 2000/9/24
Updated in MMDB: 2007/11
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Molecular Components in 1FWQ
Label Count Molecule
Protein (1 molecule)
1
Guanine Nucleotide Exchange Factor(Gene symbol: RABIF)
Molecule annotation
Chemical (1 molecule)
1
1
* Click molecule labels to explore molecular sequence information.

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