Structural highlights
3dhw is a 8 chain structure with sequence from Ecoli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Related: | 3dhx |
| Gene: | metI, yaeE, b0198, JW0194 (ECOLI), metN, abc, b0199, JW0195 (ECOLI) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[METI_ECOLI] Part of the binding-protein-dependent transport system for D-methionine and the toxic methionine analog alpha-methyl-methionine. Probably responsible for the translocation of the substrate across the membrane. [METN_ECOLI] Part of the ABC transporter complex MetNIQ involved in methionine import. Responsible for energy coupling to the transport system (Probable). It has also been shown to be involved in formyl-L-methionine transport.[1] [2]
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
The crystal structure of the high-affinity Escherichia coli MetNI methionine uptake transporter, a member of the adenosine triphosphate (ATP)-binding cassette (ABC) family, has been solved to 3.7 angstrom resolution. The overall architecture of MetNI reveals two copies of the adenosine triphosphatase (ATPase) MetN in complex with two copies of the transmembrane domain MetI, with the transporter adopting an inward-facing conformation exhibiting widely separated nucleotide binding domains. Each MetI subunit is organized around a core of five transmembrane helices that correspond to a subset of the helices observed in the larger membrane-spanning subunits of the molybdate (ModBC) and maltose (MalFGK) ABC transporters. In addition to the conserved nucleotide binding domain of the ABC family, MetN contains a carboxyl-terminal extension with a ferredoxin-like fold previously assigned to a conserved family of regulatory ligand-binding domains. These domains separate the nucleotide binding domains and would interfere with their association required for ATP binding and hydrolysis. Methionine binds to the dimerized carboxyl-terminal domain and is shown to inhibit ATPase activity. These observations are consistent with an allosteric regulatory mechanism operating at the level of transport activity, where increased intracellular levels of the transported ligand stabilize an inward-facing, ATPase-inactive state of MetNI to inhibit further ligand translocation into the cell.
The high-affinity E. coli methionine ABC transporter: structure and allosteric regulation.,Kadaba NS, Kaiser JT, Johnson E, Lee A, Rees DC Science. 2008 Jul 11;321(5886):250-3. PMID:18621668[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Gal J, Szvetnik A, Schnell R, Kalman M. The metD D-methionine transporter locus of Escherichia coli is an ABC transporter gene cluster. J Bacteriol. 2002 Sep;184(17):4930-2. PMID:12169620
- ↑ Zhang Z, Feige JN, Chang AB, Anderson IJ, Brodianski VM, Vitreschak AG, Gelfand MS, Saier MH Jr. A transporter of Escherichia coli specific for L- and D-methionine is the prototype for a new family within the ABC superfamily. Arch Microbiol. 2003 Aug;180(2):88-100. Epub 2003 Jun 19. PMID:12819857 doi:http://dx.doi.org/10.1007/s00203-003-0561-4
- ↑ Kadaba NS, Kaiser JT, Johnson E, Lee A, Rees DC. The high-affinity E. coli methionine ABC transporter: structure and allosteric regulation. Science. 2008 Jul 11;321(5886):250-3. PMID:18621668 doi:http://dx.doi.org/321/5886/250
