Fig. 3: A comparison of structural domains of POGLUTs including Rumi.
From: Structure, function, and pathology of protein O-glucosyltransferases
A O-glucosyltransferases have a signal peptide (SP) at the beginning of sequence, a CAP10 domain, and a ER-retention signal. Both KTEL and REEL retention signals have a lower affinity for ERD receptors than the KDEL signal. POGLUT1 shares 52% identity with Rumi and is the only enzyme that can rescue O-glucosylation function in rumi mutant flies. Although POGLUT2 and 3 show O-glucosyltransferase activity, but both enzymes are unable to rescue Rumi loss-of-function phenotype and only share 24% and 20.3% identity with POGLUT1, respectively, indicating different target sequence for modification. B Multiple sequence alignment of glucosyltransferases indicates the presence of DXD-like motifs, whose mutation can abolish O-glucosylation activity of enzymes. Moreover, POGLUT 2/3 lacks the WEGG motif considered necessary for UDP-glucose binding.
