Protein Domain : Sigma factor binding protein 1/2 IPR039335

Type	Family
Description	This entry represents a group of plant proteins, including Sigma factor binding protein 1/2 (SIB1/2) from Arabidopsis. They belong to the large plant-specific VQ motif-containing protein family. SIB1 is a component of the RNA polymerase machinery responsible for transcription of plastid genes []. SIB1 and SIB2 function as activators of WRKY33 in plant defense against necrotrophic pathogens [].In general, Arabidopsis VQPs interacted specifically with the C-terminal WRKY domains of group I and the sole WRKY domains of group IIc WRKY transcription factors [ , ]. Arabidopsis VQPs reported to control stress responses include the calmodulin (CaM)-binding protein CamBP25 and VQ9, which regulate osmotic and salinity tolerance, respectively, the sigma factor binding proteins SIB1 and SIB2, which act as activators of WRKY33 in plant defence, and the negative regulator of the jasmonate defence pathway [].
Short Name	SIB1/2