Medina-Aparicio Liliana, Rodriguez-Gutierrez Sarahí, Rebollar-Flores Javier E, Martínez-Batallar Ángel G, Mendoza-Mejía Blanca D, Aguirre-Partida Eira D, Vázquez Alejandra, Encarnación Sergio, Calva Edmundo, Hernández-Lucas Ismael
Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
Front Microbiol. 2021 Mar 29;12:657404. doi: 10.3389/fmicb.2021.657404. eCollection 2021.
The CRISPR-Cas cluster is found in many prokaryotic genomes including those of the Enterobacteriaceae family. serovar Typhi (. Typhi) harbors a Type I-E CRISPR-Cas locus composed of , , , , , , , , and a CRISPR1 array. In this work, it was determined that, in the absence of or , the amount of the OmpC porin decreased substantially, whereas in individual , , , or null mutants, the OmpF porin was not observed in an electrophoretic profile of outer membrane proteins. Furthermore, the LysR-type transcriptional regulator LeuO was unable to positively regulate the expression of the quiescent OmpS2 porin, in individual . Typhi , , , , , and mutants. Remarkably, the expression of the master porin regulator OmpR was dependent on the Cse2, Cas5, Cas6e, Cas1, Cas2, and Cas3 proteins. Therefore, the data suggest that the CRISPR-Cas system acts hierarchically on OmpR to control the synthesis of outer membrane proteins in . Typhi.
CRISPR-Cas 簇存在于许多原核生物基因组中,包括肠杆菌科的那些基因组。伤寒沙门氏菌(. Typhi)含有一个由 、 、 、 、 、 、 、 组成的 I-E 型 CRISPR-Cas 基因座以及一个 CRISPR1 阵列。在这项研究中,确定在没有 或 的情况下,OmpC 孔蛋白的量大幅减少,而在单个 、 、 或 缺失突变体中,在外膜蛋白的电泳图谱中未观察到 OmpF 孔蛋白。此外,在单个. Typhi 、 、 、 、 和 突变体中,LysR 型转录调节因子 LeuO 无法正向调节静止的 OmpS2 孔蛋白的表达。值得注意的是,主要孔蛋白调节因子 OmpR 的表达依赖于 Cse2、Cas5、Cas6e、Cas1、Cas2 和 Cas3 蛋白。因此,数据表明 CRISPR-Cas 系统在 OmpR 上分层作用,以控制. Typhi 中外膜蛋白的合成。