Structural highlights
Function
[AQPZ_ECOLI] Channel that permits osmotically driven movement of water in both directions. It is involved in the osmoregulation and in the maintenance of cell turgor during volume expansion in rapidly growing cells. It mediates rapid entry or exit of water in response to abrupt changes in osmolarity.[1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Aquaporins are a family of water and small molecule channels found in organisms ranging from bacteria to animals. One of these channels, the E. coli protein aquaporin Z (AqpZ), has been shown to selectively conduct only water at high rates. We have expressed, purified, crystallized, and solved the X-ray structure of AqpZ. The 2.5 A resolution structure of AqpZ suggests aquaporin selectivity results both from a steric mechanism due to pore size and from specific amino acid substitutions that regulate the preference for a hydrophobic or hydrophilic substrate. This structure provides direct evidence on the molecular mechanisms of specificity between water and glycerol in this family of channels from a single species. It is to our knowledge the first atomic resolution structure of a recombinant aquaporin and so provides a platform for combined genetic, mutational, functional, and structural determinations of the mechanisms of aquaporins and, more generally, the assembly of multimeric membrane proteins.
Architecture and selectivity in aquaporins: 2.5 a X-ray structure of aquaporin Z.,Savage DF, Egea PF, Robles-Colmenares Y, O'Connell JD 3rd, Stroud RM PLoS Biol. 2003 Dec;1(3):E72. Epub 2003 Dec 22. PMID:14691544[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Delamarche C, Thomas D, Rolland JP, Froger A, Gouranton J, Svelto M, Agre P, Calamita G. Visualization of AqpZ-mediated water permeability in Escherichia coli by cryoelectron microscopy. J Bacteriol. 1999 Jul;181(14):4193-7. PMID:10400575
- ↑ Borgnia MJ, Kozono D, Calamita G, Maloney PC, Agre P. Functional reconstitution and characterization of AqpZ, the E. coli water channel protein. J Mol Biol. 1999 Sep 3;291(5):1169-79. PMID:10518952 doi:http://dx.doi.org/S0022-2836(99)93032-2
- ↑ Pohl P, Saparov SM, Borgnia MJ, Agre P. Highly selective water channel activity measured by voltage clamp: analysis of planar lipid bilayers reconstituted with purified AqpZ. Proc Natl Acad Sci U S A. 2001 Aug 14;98(17):9624-9. Epub 2001 Aug 7. PMID:11493683 doi:http://dx.doi.org/10.1073/pnas.161299398
- ↑ Savage DF, Egea PF, Robles-Colmenares Y, O'Connell JD 3rd, Stroud RM. Architecture and selectivity in aquaporins: 2.5 a X-ray structure of aquaporin Z. PLoS Biol. 2003 Dec;1(3):E72. Epub 2003 Dec 22. PMID:14691544 doi:10.1371/journal.pbio.0000072
