Structure of the mannose transporter of the bacterial phosphotransferase system
Dear Editor,The bacterial phosphoenolpyruvate (PEP):sugar phosphotransferase system (PTS) mediates the active transport and concomitant phosphorylation of carbohydrates.1 The PTS comprises two cytoplasmic phosphoryl proteins (Le.,EⅠ and HPr) and a speciesdependent variable number of sugar-specific EⅡ complexes (including ⅡA,ⅡB,and membrane-embedded subunits ⅡC/ⅡD).El and HPr transfer phosphoryl groups from PEP to the ⅡA unit.ⅡA and ⅡB sequentially transfer phosphates to sugar,which is translocated by the ⅡC/ⅡD unit.2 Bacterial PTSs are classified into four evolutionarily distinct (super) families:(i) glucose/fructose/lactose (GFL) superfamily,(ii) ascorbate/galactitol (AG) superfamily,(iii) mannose-fructose-sorbose family (man-PTS),and (iv) nontransporting dihydroxyacetone family.The crystal structures of ⅡC transporters from GFL and AG superfamilies have been reported previously.3,4 All ⅡC proteins from GFL and AG superfamilies are homodimers and use an elevator mechanism to transport substrates across the cell membrane.
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We thank Professor Nieng Yan Princeton for comments on the manuscript,Dr.Qiang Zhou Tsinghua for suggestions on cryo-EM data processing,Dr.Xiaomin Li Tsinghua for technical support during EM image acquisition,the Tsinghua University Branch of China National Center for Protein Sciences BeijingGrant 2016YFA0501103 and 2015CB910104;National Natural Science Foundation of China 31621092.We thank Dr.Xiaochun Li and Mr.Philip Schmiege UT Southwestern Medical Center for comments on the manuscript
2019-09-09（万方平台首次上网日期，不代表论文的发表时间）
共3页
680-682
