>cd04128 Spg1 Spg1p. Spg1p (septum-promoting GTPase) was first identified in the fission yeast S. pombe, where it regulates septum formation in the septation initiation network (SIN) through the cdc7 protein kinase. Spg1p is an essential gene that localizes to the spindle pole bodies. When GTP-bound, it binds cdc7 and causes it to translocate to spindle poles. Sid4p (septation initiation defective) is required for localization of Spg1p to the spindle pole body, and the ability of Spg1p to promote septum formation from any point in the cell cycle depends on Sid4p. Spg1p is negatively regulated by Byr4 and cdc16, which form a two-component GTPase activating protein (GAP) for Spg1p. The existence of a SIN-related pathway in plants has been proposed. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are

Probab=94.39 E-value=0.37 Score=27.70 Aligned_cols=84 Identities=19% Similarity=0.309 Sum_probs=52.8 Q ss_pred EEEECCCCCCHHHHHHHHHHHHCCCCCCCCCCCHHHHHHHC----CCCCCEEEEEEECCCCHHHHHCCCHHHHCC--CCE Q ss_conf 99987878688999999997607888530245202011003----788608999865178977753058367508--978 Q gi|254780824|r 36 LTLSGDLGSGKSFLARSIIRFLMHDDALEVLSPTFTLVQLY----DASIPVAHFDFYRLSSHQEVVELGFDEILN--ERI 109 (162) Q Consensus 36 i~L~GdLGaGKTtfvr~i~~~lg~~~~~~V~SPTF~l~~~Y----~~~~~i~H~DlYRL~~~~E~~~lg~~e~~~--~~i 109 (162) T Consensus 3 ivlvGd~~VGKTsLi~rf~~~~F~~~----y~~Tig~-d~~~k~i~v~~~~v~l~iwDtaGqe~f~~~-~~~y~~~a~~~ 76 (182) T cd04128 3 IGLLGDAQIGKTSLMVKYVEGEFDED----YIQTLGV-NFMEKTISIRGTEITFSIWDLGGQREFINM-LPLVCNDAVAI 76 (182) T ss_pred EEEECCCCCCHHHHHHHHHCCCCCCC----CCCCCEE-EEEEEEEEECCEEEEEEEEECCCCHHHHHH-HHHHHCCCCEE T ss_conf 99999999898999999953999999----8887338-989999999999999999867764878999-99986478789 Q ss_pred EEE-------------ECHHHHHCCCCCC Q ss_conf 999-------------9855632049954 Q gi|254780824|r 110 CII-------------EWPEIGRSLLPKK 125 (162) Q Consensus 110 ~lI-------------EWpe~~~~~lp~~ 125 (162) T Consensus 77 ilvfDit~~~Sf~~~~~w~~~i~~~~~~~ 105 (182) T cd04128 77 LFMFDLTRKSTLNSIKEWYRQARGFNKTA 105 (182) T ss_pred EEEEECCCHHHHHHHHHHHHHHHHHCCCC T ss_conf 99997899899998999999999768999

HHsearch alignment for GI: 254780824 and conserved domain: cd04128