Sandbox Reserved 1649: Difference between revisions
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NR1 and NR2A are assembled in a dimer, arranged in a back-to-back fashion, thanks to interactions between three different domains on each subunit: sites I, II and III. | NR1 and NR2A are assembled in a dimer, arranged in a back-to-back fashion, thanks to interactions between three different domains on each subunit: sites I, II and III. | ||
- Site II: The link between NR2A and NR1 is made by at least three amino acids: E530 makes a salt bridge with R755 of NR1, F524 binds K531 of NR1 by a hydrogen bond on the backbone carbonyl oxygen, and P257. | - Site II: The link between NR2A and NR1 is made by at least three amino acids: E530 (E68 in LBD) makes a salt bridge with R755 of NR1, F524 (F62 in LBD) binds K531 of NR1 by a hydrogen bond on the backbone carbonyl oxygen, and P257. | ||
- Sites I and III: the binding is established by hydrophobic residues (I514, V526, L777, L780 present on helices D and J), or by polar contacts | - Sites I and III: the binding is established by hydrophobic residues (I514 (I52 in LBD), V526 (V64 in LBD), L777, L780 present on helices D and J), or by polar contacts | ||
Depending on the kind of NR2 (A-D) linked to NR1, the affinity of NR1 for glycine can be affected. Moreover, for a particular combination of NR1 and NR2 subunits, a negative cooperativity has been observed between glycine and glutamate binding. This leads to consider a possible allosteric coupling between NR1 and NR2. Thus, the importance of the structure of NR2A to make contacts with NR1 is obvious. But mechanistic explanation about the role that subunit-subunit contacts might have in NMDA receptor activity has not been found yet. | Depending on the kind of NR2 (A-D) linked to NR1, the affinity of NR1 for glycine can be affected. Moreover, for a particular combination of NR1 and NR2 subunits, a negative cooperativity has been observed between glycine and glutamate binding. This leads to consider a possible allosteric coupling between NR1 and NR2. Thus, the importance of the structure of NR2A to make contacts with NR1 is obvious. But mechanistic explanation about the role that subunit-subunit contacts might have in NMDA receptor activity has not been found yet. | ||
