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AglP is a S‐adenosyl‐L‐methionine‐dependent methyltransferase that participates in the N‐glycosylation pathway of Haloferax volcanii
Author(s) -
Magidovich Hilla,
YuristDoutsch Sophie,
Konrad Zvia,
Ventura Valeria V.,
Dell Anne,
Hitchen Paul G.,
Eichler Jerry
Publication year - 2010
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2010.07090.x
Subject(s) - haloferax volcanii , biology , methyltransferase , glycosylation , methionine , biochemistry , methylation , archaea , dna , amino acid , gene
Summary 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.