1zmo: Difference between revisions

Revision as of 17:17, 21 February 2008

Apo structure of haloalcohol dehalogenase HheA of Arthrobacter sp. AD2

OverviewOverview

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.

About this StructureAbout this Structure

1ZMO is a Single protein structure of sequence from Arthrobacter sp. ad1. Full crystallographic information is available from OCA.

ReferenceReference

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., de Jong RM, Kalk KH, Tang L, Janssen DB, Dijkstra BW, J Bacteriol. 2006 Jun;188(11):4051-6. PMID:16707696

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 ==Overview==
-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.
+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.
 ==About this Structure==
@@ Line 13: / Line 13: @@
 [[Category: Arthrobacter sp. ad1]]
 [[Category: Single protein]]
-[[Category: Dijkstra, B.W.]]
+[[Category: Dijkstra, B W.]]
-[[Category: Janssen, D.B.]]
+[[Category: Janssen, D B.]]
-[[Category: Jong, R.M.de.]]
+[[Category: Jong, R M.de.]]
-[[Category: Kalk, K.H.]]
+[[Category: Kalk, K H.]]
 [[Category: Tang, L.]]
 [[Category: haloalcohol dehalogenase]]
@@ Line 22: / Line 22: @@
 [[Category: short-chain dehydrogenase/reductase family]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jan 29 17:38:08 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:17:08 2008''