Physical map location of the rffC and rffA genes of Escherichia coli.
Physical map location of the rffC and rffA genes of Escherichia coli.
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大肠杆菌 rffC 和 rffA 基因的物理图谱位置。
DOI：
10.1128/jb.175.17.5738-5739.1993
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发表时间：
1993
影响因子：
3.2
通讯作者：
Rick,PD
中科院分区：
文献类型：
--
作者：
Barr,K;Rick,PD
肠杆菌共同抗原 (ECA) 是一种由肠杆菌科所有成员合成的外膜糖脂 (3,7,9)。 ECA 的碳水化合物部分由线性杂多糖链组成，其中包含氨基糖 N-乙酰基-D-葡萄糖胺 (GlcNAc)、N-乙酰基-D-甘露糖氨基糖醛酸 (ManNAcA) 和 4-乙酰氨基-4, 6-二脱氧-D-半乳糖 (Fuc4NAc)(6, 8)。这些糖相互连接形成三糖重复单元--'3)-aD-Fuc4NAc-(1-.4)-ID-ManNAcA-(1--3'4)-aD-GlcNAc-(1-+(6)。各个杂多糖链通过磷酸二酯键与磷脂酸连接(4)。ECA合成的遗传决定因素包括位于大约85分钟处的rfe-rffgene簇。最近在粘粒 pHC79 中克隆了 rfe-rff 基因簇，并利用原始粘粒克隆和六个亚克隆进行限制性核酸内切酶作图和互补研究，建立了部分基因顺序 rfe-rffD/rffE-rffA/rffC-rffT-rffM (11) 大肠杆菌染色体的完整 DNA 序列。 Daniels 等人最近报道了 86.5 分钟，包括 rfe-rff 基因簇 (1)，三个开放阅读框 o181、o299 和 o416 被指定为 rffA 和 rffC 基因的可能编码序列（图 1）。 (TDP)-4-酮-6-脱氧-D-葡萄糖转化为 TDP-4-氨基-4, 6-二脱氧-D-半乳糖，TDP-Fuc4NAc 的直接前体，而 rffC 基因似乎参与 ECA 链延长 (12)。
Enterobacterial common antigen (ECA) is an outer-mem-brane glycolipid synthesized by all members of the Enter-obacteriaceae (3, 7, 9). The carbohydrate portion of ECA consists of a linear heteropolysaccharide chain comprising the amino sugars N-acetyl-D-glucosamine (GlcNAc), N-acetyl-D-mannosaminuronic acid (ManNAcA), and 4-acetamido-4, 6-dideoxy-D-galactose (Fuc4NAc)(6, 8). These sugars are linked to one another to form thetrisaccharide repeat unit--'3)-aD-Fuc4NAc-(1-. 4)-ID-ManNAcA-(1--3'4)-aD-GlcNAc-(l-+(6). Individual heteropolysaccharide chains are linked to phosphatidic acid through phosphodiester linkage (4). The genetic determinants of ECA synthesis include the rfe-rffgene cluster located at approximately 85 min on the Escherichia coli chromosome (5, 10). The rfe-rffgene cluster was recently cloned in the cosmid pHC79, and restriction endonuclease mapping and complementation studies utilizing the original cosmid clone and six subclones established the partial gene order rfe-rffD/rffE-rffA/rffC-rffT-rffM (11). The entire DNA sequence of the E. coli chromosome from 84.5 to 86.5 min, including the rfe-rff gene cluster, was recently reported by Daniels et al.(1). Three open reading frames, o181, o299, and o416, were designated as possible coding sequences for the rffA and rffC genes (Fig. 1). The rffA gene codes for the transaminase that catalyzes the conversion of thymidine diphosphate (TDP)-4-keto-6-deoxy-D-glucose to TDP-4-amino-4, 6-dideoxy-D-galactose, the im-mediate precursor of TDP-Fuc4NAc, whereas the rffC gene appears to be involved in ECA chain elongation (12). Exper-pRL113 pRL115