2014.06.16，我院周丛照和陈宇星教授研究组和美国UAB的吴辉教授研究组合作在Journal of Biological Chemistry上在线发表论文：Structure of a novel O-GlcNAc transferase GtfA reveals insights into the glycosylation of pneumococcal serine-rich repeat adhesins. 2014 Jun 16. pii: jbc.M114.581934.

作者：师伟伟#、江永亮#、Zhu Fan、杨益虎、邵秋燕、杨海滨、任艳敏、吴辉*、陈宇星*、周丛照*。

Abstract：Protein glycosylation catalyzed by the O-GlcNAc transferase (OGT) plays a critical role in various biological processes. In Streptococcus pneumoniae, the core enzyme GtfA and co-activator GtfB form an OGT complex to glycosylate the serine-rich repeat (SRR) of adhesin PsrP, which is involved in the infection and pathogenesis. Here we report the 2.0-Å crystal structure of GtfA, revealing a β-meander add-on domain beyond the catalytic domain. It represents a novel add-on domain, which is distinct from the all-α tetratricopeptide repeats in the only two structure-known OGTs. Structural analyses combined with binding assays indicate that this add-on domain contributes to forming an active GtfA-GtfB complex and recognizing the acceptor protein. In addition, the in vitro glycosylation system enables us to map the O-linkages to the serine residues within the first SRR of PsrP. These findings suggest that fusion with an add-on domain might be a universal mechanism for diverse OGTs that recognize varying acceptor proteins/peptides.