2ksr
From Proteopedia
NMR structures of TM domain of the n-Acetylcholine receptor b2 subunit
Structural highlights
DiseaseACHB2_HUMAN Defects in CHRNB2 are the cause of nocturnal frontal lobe epilepsy type 3 (ENFL3) [MIM:605375. ENFL3 is an autosomal dominant epilepsy characterized by nocturnal seizures with hyperkinetic automatisms and poorly organized stereotyped movements.[1] [2] FunctionACHB2_HUMAN After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane permeable to sodiun ions.[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 PubMedNicotinic acetylcholine receptors (nAChRs) are involved in fast synaptic transmission in the central and peripheral nervous system. Among the many different types of subunits in nAChRs, the beta2 subunit often combines with the alpha4 subunit to form alpha4beta2 pentameric channels, the most abundant subtype of nAChRs in the brain. Besides computational predictions, there is limited experimental data available on the structure of the beta2 subunit. Using high-resolution NMR spectroscopy, we solved the structure of the entire transmembrane domain (TM1234) of the beta2 subunit. We found that TM1234 formed a four-helix bundle in the absence of the extracellular and intracellular domains. The structure exhibited many similarities to those previously determined for the Torpedo nAChR and the bacterial ion channel GLIC. We also assessed the influence of the fourth transmembrane helix (TM4) on the rest of the domain. Although secondary structures and tertiary arrangements were similar, the addition of TM4 caused dramatic changes in TM3 dynamics and subtle changes in TM1 and TM2. Taken together, this study suggests that the structures of the transmembrane domains of these proteins are largely shaped by determinants inherent in their sequence, but their dynamics may be sensitive to modulation by tertiary and quaternary contacts. NMR structure of the transmembrane domain of the n-acetylcholine receptor beta2 subunit.,Bondarenko V, Tillman T, Xu Y, Tang P Biochim Biophys Acta. 2010 Aug;1798(8):1608-14. Epub 2010 May 2. PMID:20441771[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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