INSERM U1047, UFR de Médecine, Nîmes, France.
FEBS Lett. 2011 Aug 4;585(15):2431-6. doi: 10.1016/j.febslet.2011.07.004. Epub 2011 Jul 13.
VirB8 is a critical component of the Brucella suis type IV secretion system (T4SS). We previously showed that the transmembrane (TM) domain plays an essential role in interactions of this protein with itself and the other proteins of the T4SS. We report that a point mutation in this TM domain stabilizes homodimers of VirB8 and heterodimers with VirB10. A similar variant of Agrobacterium tumefaciens VirB8 showed the same phenotype. The B. suis VirB8 variant was unable to complement a virB8 mutant and displayed a dominant negative phenotype when expressed in wild type B. suis. We suggest that interaction of VirB8 with VirB10 could play a major role in the correct function of the B. suis VirB T4SS.
VirB8 是布鲁氏菌属 IV 型分泌系统 (T4SS) 的关键组成部分。我们之前表明，跨膜 (TM) 结构域在该蛋白与自身和 T4SS 其他蛋白的相互作用中起着至关重要的作用。我们报告称，该 TM 结构域中的一个点突变稳定了 VirB8 的同源二聚体和与 VirB10 的异源二聚体。根瘤农杆菌 VirB8 的类似变体表现出相同的表型。布鲁氏菌属 VirB8 变体无法互补 virB8 突变体，并且在野生型布鲁氏菌属中表达时表现出显性负表型。我们认为，VirB8 与 VirB10 的相互作用可能在布鲁氏菌属 VirB T4SS 的正确功能中发挥主要作用。
