1h19

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STRUCTURE OF [E271Q]LEUKOTRIENE A4 HYDROLASESTRUCTURE OF [E271Q]LEUKOTRIENE A4 HYDROLASE

Structural highlights

1h19 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.1Å
Ligands:, , ,
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]

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 PubMed

Leukotriene A(4) hydrolase/aminopeptidase is a bifunctional zinc metalloenzyme that converts the fatty acid epoxide leukotriene A(4) into leukotriene B(4), a potent chemoattractant and immune-modulating lipid mediator. Recently, the structure of leukotriene A(4) hydrolase revealed that Glu-271, which belongs to a conserved GXMEN motif in the M1 family of zinc peptidases, and Gln-136 are located at the active site. Here we report that mutagenetic replacements of Glu-271, but not Gln-136, abrogate both catalytic activities of leukotriene A(4) hydrolase. Furthermore, the 2.1 A crystal structure of [E271Q]leukotriene A(4) hydrolase revealed minimal conformational changes that could not explain the loss of enzyme function. We propose that the carboxylate of Glu-271 participates in an acid-induced opening of the epoxide moiety of leukotriene A(4) and formation of a carbocation intermediate. Moreover, Glu-271 appears to act as an N-terminal recognition site and may potentially stabilize the transition-state during turnover of peptides, a property that most likely pertains to all members of the M1 family of zinc aminopeptidases. Hence, Glu-271 is a unique example of an amino acid, which has dual and separate functions in two different catalytic reactions, involving lipid and peptide substrates, respectively.

Leukotriene A4 hydrolase/aminopeptidase. Glutamate 271 is a catalytic residue with specific roles in two distinct enzyme mechanisms.,Rudberg PC, Tholander F, Thunnissen MM, Haeggstrom JZ J Biol Chem. 2002 Jan 11;277(2):1398-404. Epub 2001 Oct 23. PMID:11675384[8]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. ↑ 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
  2. ↑ 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
  3. ↑ 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
  4. ↑ 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
  5. ↑ 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
  6. ↑ 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
  7. ↑ 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
  8. ↑ Rudberg PC, Tholander F, Thunnissen MM, Haeggstrom JZ. Leukotriene A4 hydrolase/aminopeptidase. Glutamate 271 is a catalytic residue with specific roles in two distinct enzyme mechanisms. J Biol Chem. 2002 Jan 11;277(2):1398-404. Epub 2001 Oct 23. PMID:11675384 doi:10.1074/jbc.M106577200

1h19, resolution 2.10Å

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