1htj
From Proteopedia
STRUCTURE OF THE RGS-LIKE DOMAIN FROM PDZ-RHOGEF
Structural highlights
Function[ARHGB_HUMAN] May play a role in the regulation of RhoA GTPase by guanine nucleotide-binding alpha-12 (GNA12) and alpha-13 (GNA13). Acts as guanine nucleotide exchange factor (GEF) for RhoA GTPase and may act as GTPase-activating protein (GAP) for GNA12 and GNA13. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: The multidomain PDZ-RhoGEF is one of many known guanine nucleotide exchange factors that upregulate Rho GTPases. PDZ-RhoGEF and related family members play a critical role in a molecular signaling pathway from heterotrimeric G protein-coupled receptors to Rho proteins. A approximately 200 residue RGS-like (RGSL) domain in PDZ-RhoGEF and its homologs is responsible for the direct association with Galpha12/13 proteins. To better understand structure-function relationships, we initiated crystallographic studies of the RGSL domain from human PDZ-RhoGEF. RESULTS: A recombinant construct of the RGSL domain was expressed in Escherichia coli and purified, but it did not crystallize. Alternative constructs were designed based on a novel strategy of targeting lysine and glutamic acid residues for mutagenesis to alanine. A triple-point mutant functionally identical to the wild-type protein was crystallized, and its structure was determined by the MAD method using Se-methionine (Se-Met) incorporation. A molecular model of the RGSL domain was refined at 2.2 A resolution, revealing an all-helical tertiary fold with the mutations located at intermolecular lattice contacts. CONCLUSIONS: The first nine helices adopt a fold similar to that observed for RGS proteins, although the sequence identity with other such known structures is below 20%. The last three helices are an integral extension of the RGS fold, packing tightly against helices 3 and 4 with multiple hydrophobic interactions. Comparison with RGS proteins suggests features that are likely relevant for interaction with G proteins. Finally, we conclude that the strategy used to produce crystals was beneficial and might be applicable to other proteins resistant to crystallization. Structure of the RGS-like domain from PDZ-RhoGEF: linking heterotrimeric g protein-coupled signaling to Rho GTPases.,Longenecker KL, Lewis ME, Chikumi H, Gutkind JS, Derewenda ZS Structure. 2001 Jul 3;9(7):559-69. PMID:11470431[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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