Khare Baldeep, Samal Alexandra, Vengadesan Krishnan, Rajashankar K R, Ma Xin, Huang I Hsiu, Ton-That Hung, Narayana Sthanam V L
Center for Biophysical Sciences and Engineering, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Sep 1;66(Pt 9):1096-100. doi: 10.1107/S1744309110031106. Epub 2010 Aug 28.
Sortases are cysteine transpeptidases that are essential for the assembly and anchoring of cell-surface adhesins in Gram-positive bacteria. In Streptococcus agalactiae (GBS), the pilin-specific sortase SrtC1 catalyzes the polymerization of pilins encoded by pilus island 1 (PI-1) and the housekeeping sortase SrtA is necessary for cell-wall anchoring of the resulting pilus polymers. These sortases are known to utilize different substrates for pilus polymerization and cell-wall anchoring; however, the structural correlates that dictate their substrate specificity have not yet been clearly defined. This report presents the expression, purification and crystallization of SrtC1 (SAG0647) and SrtA (SAG0961) from S. agalactiae strain 2603V/R. The GBS SrtC1 has been crystallized in three crystal forms and the GBS SrtA has been crystallized in one crystal form.
分选酶是半胱氨酸转肽酶，对革兰氏阳性菌中细胞表面粘附素的组装和锚定至关重要。在无乳链球菌（GBS）中，菌毛特异性分选酶SrtC1催化菌毛岛1（PI-1）编码的菌毛蛋白聚合，而管家分选酶SrtA对于所得菌毛聚合物的细胞壁锚定是必需的。已知这些分选酶在菌毛聚合和细胞壁锚定中利用不同的底物；然而，决定其底物特异性的结构关联尚未明确界定。本报告介绍了来自无乳链球菌2603V/R菌株的SrtC1（SAG0647）和SrtA（SAG0961）的表达、纯化和结晶。GBS SrtC1已形成三种晶体形式结晶，GBS SrtA已形成一种晶体形式结晶。
