1nu5: Difference between revisions

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[[Image:1nu5.jpg|left|200px]]<br /><applet load="1nu5" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1nu5.jpg|left|200px]]<br /><applet load="1nu5" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1nu5, resolution 1.95Å" />

'''Crystal structure of Pseudomonas sp. P51 Chloromuconate lactonizing enzyme'''<br />

==Overview==

Bacterial muconate lactonizing enzymes (MLEs) catalyze the conversion of, cis,cis-muconate as a part of the beta-ketoadipate pathway, and some MLEs, are also able to dehalogenate chlorinated muconates (Cl-MLEs). The basis, for the Cl-MLEs dehalogenating activity is still unclear. To further, elucidate the differences between MLEs and Cl-MLEs, we have solved the, structure of Pseudomonas P51 Cl-MLE at 1.95 A resolution. Comparison of, Pseudomonas MLE and Cl-MLE structures reveals the presence of a large, cavity in the Cl-MLEs. The cavity may be related to conformational changes, on substrate binding in Cl-MLEs, at Gly52. Site-directed mutagenesis on, Pseudomonas MLE core positions to the equivalent Cl-MLE residues showed, that the variant Thr52Gly was rather inactive, whereas the, Thr52Gly-Phe103Ser variant had regained part of the activity. These, residues form a hydrogen bond in the Cl-MLEs. The Cl-MLE structure, as a, result of the Thr-to-Gly change, is more flexible than MLE: As a mobile, loop closes over the active site, a conformational change at Gly52 is, observed in Cl-MLEs. The loose packing and structural motions in Cl-MLE, may be required for the rotation of the lactone ring in the active site, necessary for the dehalogenating activity of Cl-MLEs. Furthermore, we also, suggest that differences in the active site mobile loop sequence between, MLEs and Cl-MLEs result in lower active site polarity in Cl-MLEs, possibly, affecting catalysis. These changes could result in slower product release, from Cl-MLEs and make it a better enzyme for dehalogenation of substrate.

Bacterial muconate lactonizing enzymes (MLEs) catalyze the conversion of cis,cis-muconate as a part of the beta-ketoadipate pathway, and some MLEs are also able to dehalogenate chlorinated muconates (Cl-MLEs). The basis for the Cl-MLEs dehalogenating activity is still unclear. To further elucidate the differences between MLEs and Cl-MLEs, we have solved the structure of Pseudomonas P51 Cl-MLE at 1.95 A resolution. Comparison of Pseudomonas MLE and Cl-MLE structures reveals the presence of a large cavity in the Cl-MLEs. The cavity may be related to conformational changes on substrate binding in Cl-MLEs, at Gly52. Site-directed mutagenesis on Pseudomonas MLE core positions to the equivalent Cl-MLE residues showed that the variant Thr52Gly was rather inactive, whereas the Thr52Gly-Phe103Ser variant had regained part of the activity. These residues form a hydrogen bond in the Cl-MLEs. The Cl-MLE structure, as a result of the Thr-to-Gly change, is more flexible than MLE: As a mobile loop closes over the active site, a conformational change at Gly52 is observed in Cl-MLEs. The loose packing and structural motions in Cl-MLE may be required for the rotation of the lactone ring in the active site necessary for the dehalogenating activity of Cl-MLEs. Furthermore, we also suggest that differences in the active site mobile loop sequence between MLEs and Cl-MLEs result in lower active site polarity in Cl-MLEs, possibly affecting catalysis. These changes could result in slower product release from Cl-MLEs and make it a better enzyme for dehalogenation of substrate.

==About this Structure==

1NU5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_sp. Pseudomonas sp.] with MN as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Chloromuconate_cycloisomerase Chloromuconate cycloisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.5.1.7 5.5.1.7] Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1NU5 OCA].

1NU5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_sp. Pseudomonas sp.] with <scene name='pdbligand=MN:'>MN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Chloromuconate_cycloisomerase Chloromuconate cycloisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.5.1.7 5.5.1.7] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NU5 OCA].

==Reference==

Line 22:

[[Category: muconate]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20 22~~:33:~~43 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:10:04 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1nu5.jpg|left|200px]]<br /><applet load="1nu5" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1nu5.jpg|left|200px]]<br /><applet load="1nu5" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1nu5, resolution 1.95&Aring;" />
 '''Crystal structure of Pseudomonas sp. P51 Chloromuconate lactonizing enzyme'''<br />
 ==Overview==
-Bacterial muconate lactonizing enzymes (MLEs) catalyze the conversion of, cis,cis-muconate as a part of the beta-ketoadipate pathway, and some MLEs, are also able to dehalogenate chlorinated muconates (Cl-MLEs). The basis, for the Cl-MLEs dehalogenating activity is still unclear. To further, elucidate the differences between MLEs and Cl-MLEs, we have solved the, structure of Pseudomonas P51 Cl-MLE at 1.95 A resolution. Comparison of, Pseudomonas MLE and Cl-MLE structures reveals the presence of a large, cavity in the Cl-MLEs. The cavity may be related to conformational changes, on substrate binding in Cl-MLEs, at Gly52. Site-directed mutagenesis on, Pseudomonas MLE core positions to the equivalent Cl-MLE residues showed, that the variant Thr52Gly was rather inactive, whereas the, Thr52Gly-Phe103Ser variant had regained part of the activity. These, residues form a hydrogen bond in the Cl-MLEs. The Cl-MLE structure, as a, result of the Thr-to-Gly change, is more flexible than MLE: As a mobile, loop closes over the active site, a conformational change at Gly52 is, observed in Cl-MLEs. The loose packing and structural motions in Cl-MLE, may be required for the rotation of the lactone ring in the active site, necessary for the dehalogenating activity of Cl-MLEs. Furthermore, we also, suggest that differences in the active site mobile loop sequence between, MLEs and Cl-MLEs result in lower active site polarity in Cl-MLEs, possibly, affecting catalysis. These changes could result in slower product release, from Cl-MLEs and make it a better enzyme for dehalogenation of substrate.
+Bacterial muconate lactonizing enzymes (MLEs) catalyze the conversion of cis,cis-muconate as a part of the beta-ketoadipate pathway, and some MLEs are also able to dehalogenate chlorinated muconates (Cl-MLEs). The basis for the Cl-MLEs dehalogenating activity is still unclear. To further elucidate the differences between MLEs and Cl-MLEs, we have solved the structure of Pseudomonas P51 Cl-MLE at 1.95 A resolution. Comparison of Pseudomonas MLE and Cl-MLE structures reveals the presence of a large cavity in the Cl-MLEs. The cavity may be related to conformational changes on substrate binding in Cl-MLEs, at Gly52. Site-directed mutagenesis on Pseudomonas MLE core positions to the equivalent Cl-MLE residues showed that the variant Thr52Gly was rather inactive, whereas the Thr52Gly-Phe103Ser variant had regained part of the activity. These residues form a hydrogen bond in the Cl-MLEs. The Cl-MLE structure, as a result of the Thr-to-Gly change, is more flexible than MLE: As a mobile loop closes over the active site, a conformational change at Gly52 is observed in Cl-MLEs. The loose packing and structural motions in Cl-MLE may be required for the rotation of the lactone ring in the active site necessary for the dehalogenating activity of Cl-MLEs. Furthermore, we also suggest that differences in the active site mobile loop sequence between MLEs and Cl-MLEs result in lower active site polarity in Cl-MLEs, possibly affecting catalysis. These changes could result in slower product release from Cl-MLEs and make it a better enzyme for dehalogenation of substrate.
 ==About this Structure==
-NU5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_sp. Pseudomonas sp.] with MN as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Chloromuconate_cycloisomerase Chloromuconate cycloisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.5.1.7 5.5.1.7] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1NU5 OCA].
+NU5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_sp. Pseudomonas sp.] with <scene name='pdbligand=MN:'>MN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Chloromuconate_cycloisomerase Chloromuconate cycloisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.5.1.7 5.5.1.7] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NU5 OCA].
 ==Reference==
@@ Line 22: / Line 22: @@
 [[Category: muconate]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 22:33:43 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:10:04 2008''