Structural analysis of sialyltransferase PM0188 from Pasteurella multocida complexed with donor analogue and acceptor sugar.
PM0188 is a newly identified sialyltransferase from P. multocida which transfers sialic acid from cytidine 5'-monophosphonuraminic acid (CMP-NeuAc) to an acceptor sugar. Although sialyltransferases are involved in important biological functions like cell-cell recognition, cell differentiation and receptor-ligand interactions, little is known about their catalytic mechanism. Here, we report the X-ray crystal structures of PM0188 in the presence of an acceptor sugar and a donor sugar analogue, revealing the precise mechanism of sialic acid transfer. Site-directed mutagenesis, kinetic assays, and structural analysis show that Asp141, His311, Glu338, Ser355 and Ser356 are important catalytic residues; Asp141 is especially crucial as it acts as a general base. These complex structures provide insights into the mechanism of sialyltransferases and the structure-based design of specific inhibitors.
Kim
Dong-Uk
DU
Department of Biology and Protein Network Research Center, Yonsei University, Seoul, Korea.
Yoo
Ji-Ho
JH
Lee
Yong Joo
YJ
Kim
Kwan Soo
KS
Cho
Hyun-Soo
HS
D001665:Binding Sites; D002241:Carbohydrates / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D007700:Kinetics; D008958:Models, Molecular; D009438:Neuraminic Acids / Q000737:chemistry; D016979:Pasteurella multocida / Q000201:enzymology*; D017434:Protein Structure, Tertiary; D012799:Sialyltransferases / Q000737:chemistry*
D002241:Carbohydrates; D009438:Neuraminic Acids; D012799:Sialyltransferases