This family is a PH domain found on plant-specific actin-binding proteins or SCABs. SCAB proteins bind, bundle and stabilise actin filaments and regulate stomatal movement. The Ig-PH fusion domain is at the C-terminus. This domain adopts the PH fold, of seven beta-strands, beta7-beta13 and two alpha-helices, alpha1 and alpha2 arranged into a beta-barrel. The canonical phosphoinositide-binding pocket of the classic PH domain is degenerate in this fused one, and the charge on the pocket suggest that the Ig-PH domain contains a non-canonical binding site for inositol phosphates [1].

1: Plant actin-binding protein SCAB1 is dimeric actin cross-linker with atypical pleckstrin homology domain. Zhang W, Zhao Y, Guo Y, Ye K; J Biol Chem. 2012;287:11981-11990. PMID:22356912