1ZMO

Apo structure of haloalcohol dehalogenase HheA of Arthrobacter sp. AD2

Summary for 1ZMO

• Entry DOI: 10.2210/pdb1zmo/pdb
• Related: 1ZMT 1ZO8
• Descriptor: halohydrin dehalogenase (2 entities in total)
• Functional Keywords: halohydrin dehalogenase, haloalcohol dehalogenase, short-chain dehydrogenase/reductase family, lyase
• Biological source: Arthrobacter sp. AD2
• Total number of polymer chains: 8
• Total formula weight: 211608.03

Authors

de Jong, R.M.,Kalk, K.H.,Tang, L.,Janssen, D.B.,Dijkstra, B.W. (deposition date: 2005-05-10, release date: 2006-04-25, Last modification date: 2023-08-23)

Primary citation

de Jong, R.M.,Kalk, K.H.,Tang, L.,Janssen, D.B.,Dijkstra, B.W.
The X-ray structure of the haloalcohol dehalogenase HheA from Arthrobacter sp. strain AD2: insight into enantioselectivity and halide binding in the haloalcohol dehalogenase family.
J.Bacteriol., 188:4051-4056, 2006

PubMed Abstract: Haloalcohol dehalogenases are bacterial enzymes that cleave the carbon-halogen bond in short aliphatic vicinal haloalcohols, like 1-chloro-2,3-propanediol, some of which are recalcitrant environmental pollutants. They use a conserved Ser-Tyr-Arg catalytic triad to deprotonate the haloalcohol oxygen, which attacks the halogen-bearing carbon atom, producing an epoxide and a halide ion. Here, we present the X-ray structure of the haloalcohol dehalogenase HheA(AD2) from Arthrobacter sp. strain AD2 at 2.0-A resolution. Comparison with the previously reported structure of the 34% identical enantioselective haloalcohol dehalogenase HheC from Agrobacterium radiobacter AD1 shows that HheA(AD2) has a similar quaternary and tertiary structure but a much more open substrate-binding pocket. Docking experiments reveal that HheA(AD2) can bind both enantiomers of the haloalcohol substrate 1-p-nitrophenyl-2-chloroethanol in a productive way, which explains the low enantiopreference of HheA(AD2). Other differences are found in the halide-binding site, where the side chain amino group of Asn182 is in a position to stabilize the halogen atom or halide ion in HheA(AD2), in contrast to HheC, where a water molecule has taken over this role. These results broaden the insight into the structural determinants that govern reactivity and selectivity in the haloalcohol dehalogenase family.

PubMed: 16707696
DOI: 10.1128/JB.01866-05

Experimental method

X-RAY DIFFRACTION (2 Å)