Li Yinyin, Schoeffler Allyn J, Berger James M, Oakley Martha G
Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
J Mol Biol. 2010 Jan 8;395(1):11-9. doi: 10.1016/j.jmb.2009.10.040. Epub 2009 Oct 22.
MukB, a divergent structural maintenance of chromosomes (SMC) protein, is important for chromosomal segregation and condensation in gamma-proteobacteria. MukB and canonical SMC proteins share a characteristic five-domain structure. Globular N- and C-terminal domains interact to form an ATP-binding cassette-like ATPase or "head" domain, which is connected to a smaller dimerization or "hinge" domain by a long, antiparallel coiled coil. In addition to mediating dimerization, this hinge region has been implicated in both conformational flexibility and dynamic protein-DNA interactions. We report here the first crystallographic model of the MukB hinge domain. This model also contains approximately 20% of the coiled-coil domain, including an unusual coiled-coil deviation. These results will facilitate studies to clarify the roles of both the hinge and the coiled-coil domains in MukB function.
MukB是一种不同的染色体结构维持（SMC）蛋白，对γ-变形菌中的染色体分离和凝聚很重要。MukB与典型的SMC蛋白共享一个特征性的五结构域结构。球状的N端和C端结构域相互作用形成一个类似ATP结合盒的ATP酶或“头部”结构域，该结构域通过一个长的反平行卷曲螺旋与一个较小的二聚化或“铰链”结构域相连。除了介导二聚化外，这个铰链区域还与构象灵活性和动态的蛋白质-DNA相互作用有关。我们在此报告MukB铰链结构域的首个晶体学模型。该模型还包含约20%的卷曲螺旋结构域，包括一个不寻常的卷曲螺旋偏差。这些结果将有助于开展研究，以阐明铰链结构域和卷曲螺旋结构域在MukB功能中的作用。
