Ellison Aubrey J, Dempwolff Felix, Kearns Daniel B, Raines Ronald T
Department of Biology, Indiana University, Bloomington, Indiana 47405, United States.
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
ACS Infect Dis. 2020 Jul 10;6(7):1836-1843. doi: 10.1021/acsinfecdis.0c00073. Epub 2020 Jun 3.
Group A (GAS) displays cell-surface proteins that resemble human collagen. We find that a fluorophore-labeled collagen mimetic peptide (CMP) labels GAS cells but not or cells, which lack such proteins. The CMP likely engages in a heterotrimeric helix with endogenous collagen, as the nonnatural d enantiomer of the CMP does not label GAS cells. To identify a molecular target, we used reverse genetics to "knock-in" the GAS genes that encode two proteins with collagen-like domains, Scl1 and Scl2, into . The fluorescent CMP labels the cells of these strains. Moreover, these strains bind tightly to a surface of mammalian collagen. These data are consistent with streptococcal collagen forming triple helices with damaged collagen in a wound bed and thus have implications for microbial virulence.
A组（A群链球菌，GAS）显示出与人胶原蛋白相似的细胞表面蛋白。我们发现，一种荧光团标记的胶原蛋白模拟肽（CMP）可标记GAS细胞，但不能标记缺乏此类蛋白的细胞。由于CMP的非天然d对映体不能标记GAS细胞，因此CMP可能与内源性胶原蛋白形成异源三聚体螺旋。为了鉴定分子靶点，我们利用反向遗传学将编码两种具有胶原样结构域的蛋白Scl1和Scl2的GAS基因“敲入”。荧光CMP标记这些菌株的细胞。此外，这些菌株紧密结合在哺乳动物胶原蛋白表面。这些数据表明，链球菌胶原蛋白与伤口床中受损的胶原蛋白形成三螺旋，因此对微生物毒力具有重要意义。
