Xu Z, Knafels J D, Yoshino K
Department of Biological Chemistry, The University of Michigan Medical School, 1301 E. Catherine Road, Ann Arbor, Michigan 48109, USA.
Nat Struct Biol. 2000 Dec;7(12):1172-7. doi: 10.1038/82040.
SecB is a bacterial molecular chaperone involved in mediating translocation of newly synthesized polypeptides across the cytoplasmic membrane of bacteria. The crystal structure of SecB from Haemophilus influenzae shows that the molecule is a tetramer organized as a dimer of dimers. Two long channels run along the side of the molecule. These are bounded by flexible loops and lined with conserved hydrophobic amino acids, which define a suitable environment for binding non-native polypeptides. The structure also reveals an acidic region on the top surface of the molecule, several residues of which have been implicated in binding to SecA, its downstream target.
SecB是一种细菌分子伴侣，参与介导新合成的多肽穿过细菌细胞质膜的转运过程。流感嗜血杆菌SecB的晶体结构表明，该分子是一个四聚体，由两个二聚体组成。两条长通道沿着分子的侧面延伸。这些通道由柔性环界定，内部排列着保守的疏水氨基酸，为结合非天然多肽定义了合适的环境。该结构还揭示了分子顶表面的一个酸性区域，其中几个残基与它的下游靶点SecA的结合有关。
