AglP is a S-adenosyl-L-methionine-dependent methyltransferase that participates in the N-glycosylation pathway of Haloferax volcanii.
While pathways for N-glycosylation in Eukarya and Bacteria have been solved, considerably less is known of this post-translational modification in Archaea. In the halophilic archaeon Haloferax volcanii, proteins encoded by the agl genes are involved in the assembly and attachment of a pentasaccharide to select asparagine residues of the S-layer glycoprotein. AglP, originally identified based on the proximity of its encoding gene to other agl genes whose products were shown to participate in N-glycosylation, was proposed, based on sequence homology, to serve as a methyltransferase. In the present report, gene deletion and mass spectrometry were employed to reveal that AglP is responsible for adding a 14 Da moiety to a hexuronic acid found at position four of the pentasaccharide decorating the Hfx. volcanii S-layer glycoprotein. Subsequent purification of a tagged version of AglP and development of an in vitro assay to test the function of the protein confirmed that AglP is a S-adenosyl-L-methionine-dependent methyltransferase.
Magidovich
Hilla
H
Department of Life Sciences, Ben Gurion University, Beersheva, Israel.
Yurist-Doutsch
Sophie
S
Konrad
Zvia
Z
Ventura
Valeria V
VV
Dell
Anne
A
Hitchen
Paul G
PG
Eichler
Jerry
J
D019843:Archaeal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017353:Gene Deletion; D006031:Glycosylation; D019622:Haloferax volcanii / Q000201:enzymology* / Q000235:genetics; D006603:Hexuronic Acids / Q000378:metabolism; D013058:Mass Spectrometry; D008780:Methyltransferases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012645:Selenomethionine / Q000031:analogs & derivatives* / Q000378:metabolism
D019843:Archaeal Proteins; D006603:Hexuronic Acids; C069627:adenosylselenomethionine; D012645:Selenomethionine; D008780:Methyltransferases