THE MEMBRANE TOPOLOGY OF THE RHIZOBIUM-MELILOTI C4-DICARBOXYLATE PERMEASE (DCTA) AS DERIVED FROM PROTEIN FUSIONS WITH ESCHERICHIA-COLI K12 ALKALINE-PHOSPHATASE (PHOA) AND BETA-GALACTOSIDASE (LACZ)

被引：29

作者：

JORDING, D ^{[1
]}

PUHLER, A ^{[1
]}

机构：

[1] UNIV BIELEFELD, FAK BIOL, LEHRSTUHL GENET, D-33501 BIELEFELD, GERMANY

来源：

MOLECULAR AND GENERAL GENETICS | 1993年 / 241卷 / 1-2期

关键词：

RHIZOBIUM-MELILOTI; C4-DICARBOXYLATE TRANSPORT SYSTEM; PROTEIN TOPOLOGY; MONITOR PROTEIN FUSIONS; CONSERVED MOTIFS;

D O I：

10.1007/BF00280207

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The Rhizobium meliloti dctA gene encodes the C4-dicarboxylate permease which mediates uptake of C4-dicarboxylates, both in free-living and symbiotic cells. Based on the hydrophobicity of the DctA protein, 12 putative membrane spanning regions were predicted. The membrane topology was further analysed by isolating in vivo fusions of DctA to Escherichia coli alkaline phosphatase (PhoA) and E. coli beta-galactosidase (LacZ). Of 10 different fusions 7 indicated a periplasmic and 3 a cytoplasmic location of the corresponding region of the DctA protein. From these data a two-dimensional model of DctA was constructed which comprised twelve transmembrane alpha-helices with the amino-terminus and the carboxy-terminus located in the cytoplasm. In addition, four conserved amino acid motifs present in many eukaryotic and prokaryotic transport proteins were observed.

引用

页码：106 / 114

页数：9