Tom, How about Magalhaes et al., J. Protein Chem., Vol. 13, p 195?
Chad ________________________________ From: Tom Peat <tom.p...@csiro.au> To: CCP4BB@JISCMAIL.AC.UK Sent: Thursday, March 27, 2014 8:09 PM Subject: Re: [ccp4bb] question on charge charge interactions Hello Joel, I like the example of HIV protease, but in this case these Asp residues are found in the active site of the protein, and unless there is substrate (or inhibitor) in the active site, these would be solvent exposed (unless I'm looking at the wrong pair of Asp residues). In the particular case I'm looking at, I have a buried pair with no other charged residues around- no waters/ metals, just Phe, Leu, etc. Which is why I think it might be slightly more rare than most of the examples I've heard about so far. Thanks for the help. Cheers, tom -----Original Message----- From: Joel Tyndall [mailto:joel.tynd...@otago.ac.nz] Sent: Friday, 28 March 2014 12:02 PM To: Peat, Tom (CMSE, Parkville); CCP4BB@JISCMAIL.AC.UK Subject: RE: question on charge charge interactions Tom, I would think the case can be made for sharing a proton (one ionised and one not) in either case but more so for acidic residues. See HIV protease Asp-Asp as a well-established example Hope this helps J -----Original Message----- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Tom Peat Sent: Friday, 28 March 2014 12:12 p.m. To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] question on charge charge interactions Hello All, I am appealing to the community as I don't seem to be able to find through Google what I am looking for, and I just don't have the ability to look through every structure in the PDB to find this. I have what I think is an interesting case: a two domain protein structure with a mostly hydrophobic interface between the two domains- the kicker is that I have two charged residues buried in this domain and they are identical. That is, I'm looking for an Arg-Arg or Asp-Asp type interaction (not Arg-Asp) where these residues are less than 4 Angstroms apart. So I was wondering if anyone had seen this in any other structure(s)? The really interesting bit is that this interaction actually regulates the activity of the enzyme domain although the domain interface isn't that close to the catalytic site. Thanks in advance to all those who can find a reference to this kind of interaction. Cheers, tom
