title: Novel domains in NADPH oxidase subunits, sorting nexins, and PtdIns 3-kinases: binding partners of SH3 domains?
abstract: Two SH3 domain-containing cytosolic components of the NADPH oxidase, p47phox and p40phox, are shown by analyses of their sequences to contain single copies of a novel class of domain, the PX (phox) domain. Homologous domains are demonstrated to be present in the Cpk class of phosphatidylinositol 3-kinase, S. cerevisiae Bem1p, and S. pombe Scd2, and a large family of human sorting nexin 1 (SNX1) homologues. The majority of these domains contains a polyproline motif, typical of SH3 domain-binding proteins. Two further findings are reported. A third NADPH oxidase subunit, p67phox, is shown to contain four tetratricopeptide repeats (TPRs) within its N-terminal RaclGTP-binding region, and a 28 residue motif in p40phox is demonstrated to be present in protein kinase C isoforms iota/lambda and zeta, and in three ZZ domain-containing proteins.
authors.affiliation: University of Oxford, Fibrinolysis Research Unit, United Kingdom. ponting@molbiol.ox.ac.uk
authors.forename: C P
authors.initials: CP
authors.lastname: Ponting
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D019255:NADPH Oxidases / Q000737:chemistry*; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D033921:Vesicular Transport Proteins; D018909:src Homology Domains
chemical_list: D002352:Carrier Proteins; D033921:Vesicular Transport Proteins; D019255:NADPH Oxidases; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor)