Identification of two glycosyltransferases required for synthesis of membrane glycolipids in Clostridioides difficile

This is the authors' abstract. We don't add key points for this paper.

consist of monohexosyldiradylglycerol (MHDRG) (~14%), dihexosyldiradylglycerol (DHDRG) (~15%), trihexosyldiradylglycerol (THDRG) (~5%), and a unique glycolipid aminohexosyl-hexosyldiradylglycerol (HNHDRG) (~16%). Previously, we found that HexSDF are required for the synthesis of HNHDRG. The enzymes required for the synthesis of MHDRG, DHDRG, and THDRG are not known. In this study, we identified the glycosyltransferases UgtA (CDR20291_0008), which is required for the synthesis of all glycolipids, and UgtB (CDR20291_1186), which is required for the synthesis of DHDRG and THDRG. We propose a model where UgtA synthesizes only MHDRG, HexSDF synthesize HNHDRG from MHDRG, and UgtB synthesizes DHDRG and potentially THDRG from MHDRG. We also report that glycolipids are important for critical cell functions, including sporulation, cell size and morphology, maintaining membrane fluidity, colony morphology, and resistance to some membrane-targeting antimicrobials. IMPORTANCE: physiology.