3hgn is a 1 chain structure with sequence from Sus scrofa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
To help resolve long-standing questions regarding the catalytic activity of the serine proteases, the structure of porcine pancreatic elastase has been analyzed by high-resolution neutron and X-ray crystallography. To mimic the tetrahedral transition intermediate, a peptidic inhibitor was used. A single large crystal was used to collect room-temperature neutron data to 1.65 A resolution and X-ray data to 1.20 A resolution. Another crystal provided a low-temperature X-ray data set to 0.94 A resolution. The neutron data are to higher resolution than previously reported for a serine protease and the X-ray data are comparable with other studies. The neutron and X-ray data show that the hydrogen bond between His57 and Asp102 (chymotrypsin numbering) is 2.60 A in length and that the hydrogen-bonding hydrogen is 0.80-0.96 A from the histidine nitrogen. This is not consistent with a low-barrier hydrogen which is predicted to have the hydrogen midway between the donor and acceptor atom. The observed interaction between His57 and Asp102 is essentially a short but conventional hydrogen bond, sometimes described as a short ionic hydrogen bond. The neutron analysis also shows that the oxygen of the oxopropyl group of the inhibitor is present as an oxygen anion rather than a hydroxyl group, supporting the role of the "oxyanion hole" in stabilizing the tetrahedral intermediate in catalysis.
Combined High-Resolution Neutron and X-ray Analysis of Inhibited Elastase Confirms the Active-Site Oxyanion Hole but Rules against a Low-Barrier Hydrogen Bond.,Tamada T, Kinoshita T, Kurihara K, Adachi M, Ohhara T, Imai K, Kuroki R, Tada T J Am Chem Soc. 2009 Jul 15. PMID:19603802[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑Tamada T, Kinoshita T, Kurihara K, Adachi M, Ohhara T, Imai K, Kuroki R, Tada T. Combined High-Resolution Neutron and X-ray Analysis of Inhibited Elastase Confirms the Active-Site Oxyanion Hole but Rules against a Low-Barrier Hydrogen Bond. J Am Chem Soc. 2009 Jul 15. PMID:19603802 doi:10.1021/ja9028846
