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Backbone structure of transmembrane domain IX of the Na+/proline transporter PutP of Escherichia coli.

ABSTRACT: The backbone structure is determined by site-directed spin labeling, double electron electron resonance measurements of distances, and modeling in terms of a helix-loop-helix construct for a transmembrane domain that is supposed to line the translocation pathway in the 54.3 kDa Na(+)/proline symporter PutP of Escherichia coli. The conformational distribution of the spin labels is accounted for by a rotamer library. An ensemble of backbone models with a root mean-square deviation of less than 2 A is obtained. These models exhibit a pronounced kink near residue T341, which is involved in substrate binding. The kink may be associated with a hinge that allows the protein to open and close an inwardly oriented cavity.

SUBMITTER: Hilger D

PROVIDER: S-EPMC2710046 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature

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Backbone structure of transmembrane domain IX of the Na+/proline transporter PutP of Escherichia coli.

Hilger Daniel D Polyhach Yevhen Y Jung Heinrich H Jeschke Gunnar G

Biophysical journal 20090101 1

The backbone structure is determined by site-directed spin labeling, double electron electron resonance measurements of distances, and modeling in terms of a helix-loop-helix construct for a transmembrane domain that is supposed to line the translocation pathway in the 54.3 kDa Na(+)/proline symporter PutP of Escherichia coli. The conformational distribution of the spin labels is accounted for by a rotamer library. An ensemble of backbone models with a root mean-square deviation of less than 2 A ...[more]

PMID: 19134477

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