期刊
NATURE
卷 553, 期 7688, 页码 361-+出版社
NATURE PUBLISHING GROUP
DOI: 10.1038/nature25190
关键词
-
资金
- federal funds from the National Cancer Institute [ACB-12002]
- National Institute of General Medical Sciences [AGM-12006]
- National Institute of General Medical Sciences from National Institutes of Health (NIH) [P41 GM103403]
- NIH-ORIP HEI grant [S10 RR029205]
- DOE Office of Science by Argonne National Laboratory [DE-AC02-06CH11357]
- NIH grant [5R01GM110143]
- Alexander Graham Bell Canada Graduate Scholarship from Natural Sciences and Engineering Research Council
- Canadian Institutes of Health Research
- Canada Research Chair
- DOE Office of Science by Brookhaven National Laboratory [DE-SC0012704]
- NATIONAL CENTER FOR RESEARCH RESOURCES [S10RR029205] Funding Source: NIH RePORTER
- NATIONAL INSTITUTE OF BIOMEDICAL IMAGING AND BIOENGINEERING [P30EB009998] Funding Source: NIH RePORTER
- NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES [R01GM110143, P41GM103403] Funding Source: NIH RePORTER
O-antigens are cell surface polysaccharides of many Gram-negative pathogens that aid in escaping innate immune responses(1). A widespread O-antigen biosynthesis mechanism involves the synthesis of the lipid-anchored polymer on the cytosolic face of the inner membrane, followed by transport to the periplasmic side where it is ligated to the lipid A core to complete a lipopolysaccharide molecule(2). In this pathway, transport to the periplasm is mediated by an ATP-binding cassette (ABC) transporter, called Wzm-Wzt. Here we present the crystal structure of the Wzm-Wzt homologue from Aquifex aeolicus in an open conformation. The transporter forms a transmembrane channel that is sufficiently wide to accommodate a linear polysaccharide. Its nucleotide-binding domain and a periplasmic extension form 'gate helices' at the cytosolic and periplasmic membrane interfaces that probably serve as substrate entry and exit points. Site-directed mutagenesis of the gates impairs in vivo O-antigen secretion in the Escherichia coli prototype. Combined with a closed structure of the isolated nucleotide-binding domains, our structural and functional analyses suggest a processive O-antigen translocation mechanism, which stands in contrast to the classical alternating access mechanism of ABC transporters.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据