4FM4: Wild Type Fe-Type Nitrile Hydratase From Comamonas Testosteroni Ni1

Citation:
Abstract
We report herein the functional expression of an Fe-type nitrile hydratase (NHase) without the co-expression of an activator protein or the Escherichia coli chaperone proteins GroES/EL. Soluble protein was obtained when the alpha- and beta-subunit genes of the Fe-type NHase Comamonas testosteroni Ni1 (CtNHase) were synthesized with optimized E. coli codon usage and co-expressed. As a control, the Fe-type NHase from Rhodococcus equi TG328-2 (ReNHase) was expressed with (ReNHase(+Act)) and without (ReNHase(-Act)) its activator protein, establishing that expression of a fully functional, metallated ReNHase enzyme requires the co-expression of its activator protein, similar to all other Fe-type NHase enzymes reported to date, whereas the CtNHase does not. The X-ray crystal structure of CtNHase was determined to 2.4A resolution revealing an alphabeta heterodimer, similar to other Fe-type NHase enzymes, except for two important differences. First, two His residues reside in the CtNHase active site that are not observed in other Fe-type NHase enzymes and second, the active site Fe(III) ion resides at the bottom of a wide solvent exposed channel. The solvent exposed active site, along with the two active site histidine residues, are hypothesized to play a role in iron incorporation in the absence of an activator protein.
PDB ID: 4FM4Download
MMDB ID: 102197
PDB Deposition Date: 2012/6/15
Updated in MMDB: 2012/08
Experimental Method:
x-ray diffraction
Resolution: 2.38  Å
Source Organism:
Similar Structures:
Biological Unit for 4FM4: dimeric; determined by author and by software (PISA)
Molecular Components in 4FM4
Label Count Molecule
Proteins (2 molecules)
1
Nitrile Hydratase Alpha Subunit
Molecule annotation
1
Nitrile Hydratase Beta Subunit
Molecule annotation
Chemicals (2 molecules)
1
1
2
1
* Click molecule labels to explore molecular sequence information.

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