Tiennault-Desbordes E, Cenatiempo Y, Laalami S
Institut de Biologie Moléculaire et d'Ingénierie Génétique, ESA CNRS 6031, Université de Poitiers, 86022 Poitiers Cedex, France.
J Bacteriol. 2001 Jan;183(1):207-13. doi: 10.1128/JB.183.1.207-213.2001.
We have isolated the structural gene for translation initiation factor IF2 (infB) from the myxobacterium Myxococcus xanthus. The gene (3.22 kb) encodes a 1,070-residue protein showing extensive homology within its G domain and C terminus to the equivalent regions of IF2 from Escherichia coli. The protein cross-reacts with antibodies raised against E. coli IF2 and was able to complement an E. coli infB mutant. The M. xanthus protein is the largest IF2 known to date. This is essentially due to a longer N-terminal region made up of two characteristic domains. The first comprises a 188-amino-acid sequence consisting essentially of alanine, proline, valine, and glutamic acid residues, similar to the APE domain observed in Stigmatella aurantiaca IF2. The second is unique to M. xanthus IF2, is located between the APE sequence and the GTP binding domain, and consists exclusively of glycine, proline, and arginine residues.
我们从粘细菌黄色粘球菌中分离出了翻译起始因子IF2（infB）的结构基因。该基因（3.22 kb）编码一种1070个氨基酸残基的蛋白质，其G结构域和C末端与大肠杆菌IF2的相应区域具有广泛的同源性。该蛋白质与抗大肠杆菌IF2产生的抗体发生交叉反应，并能够互补大肠杆菌infB突变体。黄色粘球菌的这种蛋白质是迄今为止已知最大的IF2。这主要是由于其较长的N末端区域由两个特征性结构域组成。第一个结构域包含一个188个氨基酸的序列，主要由丙氨酸、脯氨酸、缬氨酸和谷氨酸残基组成，类似于在橙色标桩菌IF2中观察到的APE结构域。第二个结构域是黄色粘球菌IF2所特有的，位于APE序列和GTP结合结构域之间，仅由甘氨酸、脯氨酸和精氨酸残基组成。
