Crystal Structures of Phosphotransferase System Enzymes PtxB (IIIBAsc)   and PtxA (IIA(Asc)) from Streptococcus mutans

doi:10.1016/j.jmb.2008.12.046

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	Crystal Structures of Phosphotransferase System Enzymes PtxB (IIIBAsc) and PtxA (IIA(Asc)) from Streptococcus mutans
	Lei, Jian ; Li, Lan-Fen ; Su, Xiao-Dong
刊名	分子生物学杂志
	2009
关键词	phosphotransferase system sugar transport phosphorylation L-ascorbate SAD molecular replacement MANNITOL TRANSPORTER IIMANNITOL PHOSPHORYL TRANSFER COMPLEX N-TERMINAL DOMAIN ESCHERICHIA-COLI BACILLUS-SUBTILIS IIA-DOMAIN MOLECULAR REPLACEMENT MANNOSE TRANSPORTER SUGAR-TRANSPORT NMR STRUCTURE
DOI	10.1016/j.jmb.2008.12.046
英文摘要	Streptococcus mutans is the primary etiological agent of dental caries in man and other mammalian organisms. This bacterium metabolizes carbohydrates actively and thrives under anaerobic conditions by fermenting L-ascorbate (Asc) via the sga operon, which includes SgaT, PtxB, and PtxA. These three proteins are members of the Asc family of enzyme II (Ell) complexes of the bacterial phosphotransferase system. Here, we report the crystal structure of PtxB, solved by single-wavelength anomalous dispersion phasing, and that of PtxA, solved by molecular replacement, from S. mutans. PtxB provides the first crystal structure of an EIIB from the Asc family, composed of a central beta sheet of parallel strands flanked by alpha helices on both sides. The structure of PtxB is similar to the structures of IIBMtl, (IIb subunit of mannitol PTS) and IIBCel (IIB subunit of cellobiose) in Escherichia coli despite the low sequence identity. PtxA adopts a globular alpha/beta, sandwich structure. The phosphorylation-site His68 is situated between beta 2 and beta 3, within a hydrophobic pocket. We found that the hydrogen bond oil N-delta 1 of the active-site histidine is a common means of ensuring that phosphate is on the correct N-epsilon 2 site in many EIIA families. Finally, a model of the PtxB-PtxA complex was constructed, and a PtxA-phospho-PtxB state is proposed. Analyses of the two structures shed light on the catalytic mechanism of the phosphotransferase system. (C) 2008 Elsevier Ltd. All rights reserved.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000263803800016&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; Biochemistry & Molecular Biology; SCI(E); PubMed; 4; ARTICLE; 2; 465-475; 386
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/197307]
专题	生命科学学院
推荐引用方式 GB/T 7714	Lei, Jian,Li, Lan-Fen,Su, Xiao-Dong. Crystal Structures of Phosphotransferase System Enzymes PtxB (IIIBAsc) and PtxA (IIA(Asc)) from Streptococcus mutans[J]. 分子生物学杂志,2009.
APA	Lei, Jian,Li, Lan-Fen,&Su, Xiao-Dong.(2009).Crystal Structures of Phosphotransferase System Enzymes PtxB (IIIBAsc) and PtxA (IIA(Asc)) from Streptococcus mutans.分子生物学杂志.
MLA	Lei, Jian,et al."Crystal Structures of Phosphotransferase System Enzymes PtxB (IIIBAsc) and PtxA (IIA(Asc)) from Streptococcus mutans".分子生物学杂志 (2009).