1eke
From Proteopedia
(New page: 200px<br /><applet load="1eke" size="450" color="white" frame="true" align="right" spinBox="true" caption="1eke, resolution 2.00Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1eke.gif|left|200px]]<br /><applet load="1eke" size=" | + | [[Image:1eke.gif|left|200px]]<br /><applet load="1eke" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1eke, resolution 2.00Å" /> | caption="1eke, resolution 2.00Å" /> | ||
'''CRYSTAL STRUCTURE OF CLASS II RIBONUCLEASE H (RNASE HII) WITH MES LIGAND'''<br /> | '''CRYSTAL STRUCTURE OF CLASS II RIBONUCLEASE H (RNASE HII) WITH MES LIGAND'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: RNases H are present in all organisms and cleave RNAs in | + | BACKGROUND: RNases H are present in all organisms and cleave RNAs in RNA/DNA hybrids. There are two major types of RNases H that have little similarity in sequence, size and specificity. The structure of RNase HI, the smaller enzyme and most abundant in bacteria, has been extensively studied. However, no structural information is available for the larger RNase H, which is most abundant in eukaryotes and archaea. Mammalian RNase H participates in DNA replication, removal of the Okazaki fragments and possibly DNA repair. RESULTS: The crystal structure of RNase HII from the hypothermophile Methanococcus jannaschii, which is homologous to mammalian RNase H, was solved using a multiwavelength anomalous dispersion (MAD) phasing method at 2 A resolution. The structure contains two compact domains. Despite the absence of sequence similarity, the large N-terminal domain shares a similar fold with the RNase HI of bacteria. The active site of RNase HII contains three aspartates: Asp7, Asp112 and Asp149. The nucleotide-binding site is located in the cleft between the N-terminal and C-terminal domains. CONCLUSIONS: Despite a lack of any detectable similarity in primary structure, RNase HII shares a similar structural domain with RNase HI, suggesting that the two classes of RNases H have a common catalytic mechanism and possibly a common evolutionary origin. The involvement of the unique C-terminal domain in substrate recognition explains the different reaction specificity observed between the two classes of RNase H. |
==About this Structure== | ==About this Structure== | ||
| - | 1EKE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanocaldococcus_jannaschii Methanocaldococcus jannaschii] with MES as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ribonuclease_H Ribonuclease H], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.26.4 3.1.26.4] Full crystallographic information is available from [http:// | + | 1EKE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanocaldococcus_jannaschii Methanocaldococcus jannaschii] with <scene name='pdbligand=MES:'>MES</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ribonuclease_H Ribonuclease H], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.26.4 3.1.26.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EKE OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Ribonuclease H]] | [[Category: Ribonuclease H]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: BSGC, Berkeley | + | [[Category: BSGC, Berkeley Structural Genomics Center.]] |
| - | [[Category: Hung, L | + | [[Category: Hung, L W.]] |
[[Category: Kim, R.]] | [[Category: Kim, R.]] | ||
| - | [[Category: Kim, S | + | [[Category: Kim, S H.]] |
| - | [[Category: Lai, L | + | [[Category: Lai, L H.]] |
[[Category: Yokota, H.]] | [[Category: Yokota, H.]] | ||
[[Category: MES]] | [[Category: MES]] | ||
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[[Category: structural genomics]] | [[Category: structural genomics]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:28:38 2008'' |
Revision as of 10:28, 21 February 2008
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CRYSTAL STRUCTURE OF CLASS II RIBONUCLEASE H (RNASE HII) WITH MES LIGAND
Overview
BACKGROUND: RNases H are present in all organisms and cleave RNAs in RNA/DNA hybrids. There are two major types of RNases H that have little similarity in sequence, size and specificity. The structure of RNase HI, the smaller enzyme and most abundant in bacteria, has been extensively studied. However, no structural information is available for the larger RNase H, which is most abundant in eukaryotes and archaea. Mammalian RNase H participates in DNA replication, removal of the Okazaki fragments and possibly DNA repair. RESULTS: The crystal structure of RNase HII from the hypothermophile Methanococcus jannaschii, which is homologous to mammalian RNase H, was solved using a multiwavelength anomalous dispersion (MAD) phasing method at 2 A resolution. The structure contains two compact domains. Despite the absence of sequence similarity, the large N-terminal domain shares a similar fold with the RNase HI of bacteria. The active site of RNase HII contains three aspartates: Asp7, Asp112 and Asp149. The nucleotide-binding site is located in the cleft between the N-terminal and C-terminal domains. CONCLUSIONS: Despite a lack of any detectable similarity in primary structure, RNase HII shares a similar structural domain with RNase HI, suggesting that the two classes of RNases H have a common catalytic mechanism and possibly a common evolutionary origin. The involvement of the unique C-terminal domain in substrate recognition explains the different reaction specificity observed between the two classes of RNase H.
About this Structure
1EKE is a Single protein structure of sequence from Methanocaldococcus jannaschii with as ligand. Active as Ribonuclease H, with EC number 3.1.26.4 Full crystallographic information is available from OCA.
Reference
Crystal structure of archaeal RNase HII: a homologue of human major RNase H., Lai L, Yokota H, Hung LW, Kim R, Kim SH, Structure. 2000 Aug 15;8(8):897-904. PMID:10997908
Page seeded by OCA on Thu Feb 21 12:28:38 2008
Categories: Methanocaldococcus jannaschii | Ribonuclease H | Single protein | BSGC, Berkeley Structural Genomics Center. | Hung, L W. | Kim, R. | Kim, S H. | Lai, L H. | Yokota, H. | MES | Berkeley structural genomics center | Bsgc structure funded by nih | Endonuclease | Nuclease | Protein structure initiative | Psi | Structural genomics
