1rga
From Proteopedia
(New page: 200px<br /><applet load="1rga" size="450" color="white" frame="true" align="right" spinBox="true" caption="1rga, resolution 1.7Å" /> '''CRYSTAL STRUCTURE OF ...) |
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| - | [[Image:1rga.gif|left|200px]]<br /><applet load="1rga" size=" | + | [[Image:1rga.gif|left|200px]]<br /><applet load="1rga" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1rga, resolution 1.7Å" /> | caption="1rga, resolution 1.7Å" /> | ||
'''CRYSTAL STRUCTURE OF RNASE T1 WITH 3'-GMP AND GUANOSINE: A PRODUCT COMPLEX'''<br /> | '''CRYSTAL STRUCTURE OF RNASE T1 WITH 3'-GMP AND GUANOSINE: A PRODUCT COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
| - | A modified method for the synthesis and separation of endo and exo | + | A modified method for the synthesis and separation of endo and exo guanosine 2',3'-cyclophosphorothioate (cGPS) has been developed. The exo diastereoisomer has been co-crystallized with RNase T1. cGPS is known to be a RNase T1 inhibitor but is also a very slow substrate. It was hydrolyzed during the crystallization, leaving 3'-guanylic acid (3'-GMP) in the active site. As a guanosine was also found to be bound in a subsite, the enzyme contains the products of the reaction of guanylyl-3',5'-guanosine. The structure was refined to a resolution of 1.7 A and yielded a final R value of 14.5%. In contrast to previous 3'-GMP complexes of RNase T1, the ribose phosphate moiety of the inhibitor is in contact with all the active site residues. The phosphate forms hydrogen bonds with Asn36, Tyr38, Arg77, His92, and with Asn49 from a symmetry-related molecule. The ribose 2'-OH is hydrogen-bonded to both Glu58 and His40. The interactions in the active site of the present structure are compared to those found in the 2'-GMP complex of RNase T1. |
==About this Structure== | ==About this Structure== | ||
| - | 1RGA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aspergillus_oryzae Aspergillus oryzae] with CA, 3GP and G as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonuclease_T(1) Ribonuclease T(1)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.27.3 3.1.27.3] Full crystallographic information is available from [http:// | + | 1RGA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aspergillus_oryzae Aspergillus oryzae] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=3GP:'>3GP</scene> and <scene name='pdbligand=G:'>G</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonuclease_T(1) Ribonuclease T(1)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.27.3 3.1.27.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RGA OCA]. |
==Reference== | ==Reference== | ||
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[[Category: hydrolase(endoribonuclease)]] | [[Category: hydrolase(endoribonuclease)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:50:34 2008'' |
Revision as of 12:50, 21 February 2008
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CRYSTAL STRUCTURE OF RNASE T1 WITH 3'-GMP AND GUANOSINE: A PRODUCT COMPLEX
Overview
A modified method for the synthesis and separation of endo and exo guanosine 2',3'-cyclophosphorothioate (cGPS) has been developed. The exo diastereoisomer has been co-crystallized with RNase T1. cGPS is known to be a RNase T1 inhibitor but is also a very slow substrate. It was hydrolyzed during the crystallization, leaving 3'-guanylic acid (3'-GMP) in the active site. As a guanosine was also found to be bound in a subsite, the enzyme contains the products of the reaction of guanylyl-3',5'-guanosine. The structure was refined to a resolution of 1.7 A and yielded a final R value of 14.5%. In contrast to previous 3'-GMP complexes of RNase T1, the ribose phosphate moiety of the inhibitor is in contact with all the active site residues. The phosphate forms hydrogen bonds with Asn36, Tyr38, Arg77, His92, and with Asn49 from a symmetry-related molecule. The ribose 2'-OH is hydrogen-bonded to both Glu58 and His40. The interactions in the active site of the present structure are compared to those found in the 2'-GMP complex of RNase T1.
About this Structure
1RGA is a Single protein structure of sequence from Aspergillus oryzae with , and as ligands. Active as Ribonuclease T(1), with EC number 3.1.27.3 Full crystallographic information is available from OCA.
Reference
Crystal structure of RNase T1 with 3'-guanylic acid and guanosine., Zegers I, Haikal AF, Palmer R, Wyns L, J Biol Chem. 1994 Jan 7;269(1):127-33. PMID:8276784
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