Structure-function of cyanobacterial outer-membrane protein, Slr1270: homolog of Escherichia coli drug export/colicin import protein, TolC.
FEBS Lett
; 588(21): 3793-801, 2014 Nov 03.
Article
in En
| MEDLINE
| ID: mdl-25218435
ABSTRACT
Compared to thylakoid and inner membrane proteins in cyanobacteria, no structure-function information is available presently for integral outer-membrane proteins (OMPs). The Slr1270 protein from the cyanobacterium Synechocystis 6803, over-expressed in Escherichia coli, was refolded, and characterized for molecular size, secondary structure, and ion-channel function. Refolded Slr1270 displays a single band in native-electrophoresis, has an α-helical content of 50-60%, as in E. coli TolC with which it has significant secondary-structure similarity, and an ion-channel function with a single-channel conductance of 80-200pS, and a monovalent ion (K(+)Cl(-)) selectivity of 4.71. The pH-dependence of channel conductance implies a role for carboxylate residues in channel gating, analogous to that in TolC.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Membrane Transport Proteins
/
Bacterial Outer Membrane Proteins
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Sequence Homology, Amino Acid
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Escherichia coli Proteins
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Synechocystis
Language:
En
Journal:
FEBS Lett
Year:
2014
Document type:
Article
Affiliation country: