Structure of a MacAB-like efflux pump from Streptococcus pneumoniae

• DOI: 10.1038/s41467-017-02741-4
• Publication Date: 2018-01-09T14:40:18Z
• Authors: Hong-Bo Yang; Wen-Tao Hou; Meng-Ting Cheng; Yong-Liang Jiang; Yuxing Chen; Cong-Zhao Zhou
• Keywords: Efflux; Helix (gastropod)

The spr0693-spr0694-spr0695 operon of Streptococcus pneumoniae encodes a putative ATP-binding cassette (ABC)-type efflux pump involved in the resistance antibiotics and antimicrobial peptides. Here we report crystal structures Spr0694-0695 at 3.3 Å Spr0693 3.0 resolution, revealing MacAB-like pump. dimeric adopts non-canonical fold ABC transporter, transmembrane domain which consists eight tightly packed helices with an insertion extracellular between first second helices, whereas forms nanotube channel docked onto transporter. Structural analyses combined ATPase activity susceptibility assays, enable us to propose substrate-entrance tunnel lateral access controlled by guard helix. Altogether, our findings provide structural insights transport mechanism Gram-positive bacteria.