| Structural highlights
5ni6 is a 1 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , , , |
| Related: | 4ms6, 4dpr, 5ni2, 5ni4 |
| Activity: | Leukotriene-A(4) hydrolase, with EC number 3.3.2.6 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[LKHA4_HUMAN] Epoxide hydrolase that catalyzes the final step in the biosynthesis of the proinflammatory mediator leukotriene B4. Has also aminopeptidase activity.[1] [2] [3] [4] [5] [6] [7]
Publication Abstract from PubMed
Human leukotriene (LT) A4 hydrolase/aminopeptidase (LTA4H) is a bifunctional enzyme that converts the highly unstable epoxide intermediate LTA4 into LTB4, a potent leukocyte activating agent, while the aminopeptidase activity cleaves and inactivates the chemotactic tripeptide Pro-Gly-Pro. Here, we describe high-resolution crystal structures of LTA4H complexed with LTA4, providing the structural underpinnings of the enzyme's unique epoxide hydrolase (EH) activity, involving Zn2+, Y383, E271, D375, and two catalytic waters. The structures reveal that a single catalytic water is involved in both catalytic activities of LTA4H, alternating between epoxide ring opening and peptide bond hydrolysis, assisted by E271 and E296, respectively. Moreover, we have found two conformations of LTA4H, uncovering significant domain movements. The resulting structural alterations indicate that LTA4 entrance into the active site is a dynamic process that includes rearrangement of three moving domains to provide fast and efficient alignment and processing of the substrate. Thus, the movement of one dynamic domain widens the active site entrance, while another domain acts like a lid, opening and closing access to the hydrophobic tunnel, which accommodates the aliphatic tale of LTA4 during EH reaction. The enzyme-LTA4 complex structures and dynamic domain movements provide critical insights for development of drugs targeting LTA4H.
Capturing LTA4 hydrolase in action: Insights to the chemistry and dynamics of chemotactic LTB4 synthesis.,Stsiapanava A, Samuelsson B, Haeggstrom JZ Proc Natl Acad Sci U S A. 2017 Aug 21. pii: 201710850. doi:, 10.1073/pnas.1710850114. PMID:28827365[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Odlander B, Claesson HE, Bergman T, Radmark O, Jornvall H, Haeggstrom JZ. Leukotriene A4 hydrolase in the human B-lymphocytic cell line Raji: indications of catalytically divergent forms of the enzyme. Arch Biochem Biophys. 1991 May 15;287(1):167-74. PMID:1897988
- ↑ Toh H, Minami M, Shimizu T. Molecular evolution and zinc ion binding motif of leukotriene A4 hydrolase. Biochem Biophys Res Commun. 1990 Aug 31;171(1):216-21. PMID:1975494
- ↑ Haeggstrom JZ, Wetterholm A, Shapiro R, Vallee BL, Samuelsson B. Leukotriene A4 hydrolase: a zinc metalloenzyme. Biochem Biophys Res Commun. 1990 Nov 15;172(3):965-70. PMID:2244921
- ↑ Thunnissen MM, Andersson B, Samuelsson B, Wong CH, Haeggstrom JZ. Crystal structures of leukotriene A4 hydrolase in complex with captopril and two competitive tight-binding inhibitors. FASEB J. 2002 Oct;16(12):1648-50. Epub 2002 Aug 7. PMID:12207002 doi:10.1096/fj.01-1017fje
- ↑ Rudberg PC, Tholander F, Thunnissen MM, Samuelsson B, Haeggstrom JZ. Leukotriene A4 hydrolase: selective abrogation of leukotriene B4 formation by mutation of aspartic acid 375. Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4215-20. Epub 2002 Mar 26. PMID:11917124 doi:10.1073/pnas.072090099
- ↑ Rudberg PC, Tholander F, Andberg M, Thunnissen MM, Haeggstrom JZ. Leukotriene A4 hydrolase: identification of a common carboxylate recognition site for the epoxide hydrolase and aminopeptidase substrates. J Biol Chem. 2004 Jun 25;279(26):27376-82. Epub 2004 Apr 12. PMID:15078870 doi:10.1074/jbc.M401031200
- ↑ Tholander F, Muroya A, Roques BP, Fournie-Zaluski MC, Thunnissen MM, Haeggstrom JZ. Structure-based dissection of the active site chemistry of leukotriene A4 hydrolase: implications for M1 aminopeptidases and inhibitor design. Chem Biol. 2008 Sep 22;15(9):920-9. PMID:18804029 doi:10.1016/j.chembiol.2008.07.018
- ↑ Stsiapanava A, Samuelsson B, Haeggstrom JZ. Capturing LTA4 hydrolase in action: Insights to the chemistry and dynamics of chemotactic LTB4 synthesis. Proc Natl Acad Sci U S A. 2017 Aug 21. pii: 201710850. doi:, 10.1073/pnas.1710850114. PMID:28827365 doi:http://dx.doi.org/10.1073/pnas.1710850114
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