Topological analysis of an RND family transporter, MexD of Pseudomonas aeruginosa

FEBS Letters

Gotoh, Naomasa¹  Wada, Takaomi¹  Kusumi, Toshiyuki¹  Nishino, Takeshi¹  Tsujimoto, Hideto¹ 

[1] Department of Microbiology, Kyoto Pharmaceutical University, Yamashina, Kyoto 607-8414, Japan

关键词: Multidrug efflux;    MexD;    Topology;    Resistance-nodulation-division family;    Pseudomonas aeruginosa;   

DOI  :  10.1016/S0014-5793(99)01116-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The membrane topology of a resistance-nodulation-division (RND) family transporter, MexD of Pseudomonas aeruginosa, was determined. Although it had been predicted previously that most RND proteins contain 12 transmembrane helices, three independent computer programs used in the present study predicted that MexD possessed 11, 14 or 17 transmembrane segments. To investigate the topology of MexD more thoroughly, 25 MexD-PhoA (alkaline phosphatase) and 18 MexD-Bla (β-lactamase) fusion plasmids were constructed and analyzed. The resulting topological model had just 12 transmembrane helices and two periplasmic loops of about 300 residues between helices 1 and 2 and helices 7 and 8. It is therefore proposed that the N- and C-termini are located in the cytoplasm and the predicted orientation is consistent with the ‘positive-inside rule’. This topological model can be applied to other RND proteins.

【 授权许可】

Unknown