Structure of 6-Aminohexanoate-dimer Hydrolase, S112A/G181D Mutant Complexed with 6-Aminohexanoate-dimerStructure of 6-Aminohexanoate-dimer Hydrolase, S112A/G181D Mutant Complexed with 6-Aminohexanoate-dimer

Structural highlights

2zm7 is a 1 chain structure with sequence from Flavobacterium sp.. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.6Å
Ligands:, , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NYLB2_FLASK Involved in nylon oligomer degradation.[1] [2] NYLB_FLASK

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

A carboxylesterase with a beta-lactamase fold from Arthrobacter possesses a low level of hydrolytic activity (0.023 mumol.min(-1).mg(-1)) when acting on a 6-aminohexanoate linear dimer byproduct of the nylon-6 industry (Ald). G181D/H266N/D370Y triple mutations in the parental esterase increased the Ald-hydrolytic activity 160-fold. Kinetic studies showed that the triple mutant possesses higher affinity for the substrate Ald (K(m) = 2.0 mm) than the wild-type Ald hydrolase from Arthrobacter (K(m) = 21 mm). In addition, the k(cat)/K(m) of the mutant (1.58 s(-1).mm(-1)) was superior to that of the wild-type enzyme (0.43 s(-1).mm(-1)), demonstrating that the mutant efficiently converts the unnatural amide compounds even at low substrate concentrations, and potentially possesses an advantage for biotechnological applications. X-ray crystallographic analyses of the G181D/H266N/D370Y enzyme and the inactive S112A-mutant-Ald complex revealed that Ald binding induces rotation of Tyr370/His375, movement of the loop region (N167-V177), and flip-flop of Tyr170, resulting in the transition from open to closed forms. From the comparison of the three-dimensional structures of various mutant enzymes and site-directed mutagenesis at positions 266 and 370, we now conclude that Asn266 makes suitable contacts with Ald and improves the electrostatic environment at the N-terminal region of Ald cooperatively with Asp181, and that Tyr370 stabilizes Ald binding by hydrogen-bonding/hydrophobic interactions at the C-terminal region of Ald.

Molecular design of a nylon-6 byproduct-degrading enzyme from a carboxylesterase with a beta-lactamase fold.,Kawashima Y, Ohki T, Shibata N, Higuchi Y, Wakitani Y, Matsuura Y, Nakata Y, Takeo M, Kato D, Negoro S FEBS J. 2009 May;276(9):2547-56. Epub 2009 Mar 18. PMID:19476493[3]

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

See Also

References

  1. Negoro S, Nakamura S, Kimura H, Fujiyama K, Zhang YZ, Kanzaki N, Okada H. Construction of hybrid genes of 6-aminohexanoic acid-oligomer hydrolase and its analogous enzyme. Estimation of the intramolecular regions important for the enzyme evolution. J Biol Chem. 1984 Nov 25;259(22):13648-51 PMID:6389532
  2. Okada H, Negoro S, Kimura H, Nakamura S. Evolutionary adaptation of plasmid-encoded enzymes for degrading nylon oligomers. Nature. 1983 Nov 10-16;306(5939):203-6. PMID:6646204 doi:10.1038/306203a0
  3. Kawashima Y, Ohki T, Shibata N, Higuchi Y, Wakitani Y, Matsuura Y, Nakata Y, Takeo M, Kato D, Negoro S. Molecular design of a nylon-6 byproduct-degrading enzyme from a carboxylesterase with a beta-lactamase fold. FEBS J. 2009 May;276(9):2547-56. Epub 2009 Mar 18. PMID:19476493 doi:10.1111/j.1742-4658.2009.06978.x

2zm7, resolution 1.60Å

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