1rdd

<table><tr><td colspan='2'>[[1rdd]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RDD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1RDD FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Ribonuclease_H Ribonuclease H], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.26.4 3.1.26.4] </span></td></tr>

[[https://www.uniprot.org/uniprot/RNH_ECOLI RNH_ECOLI]] Endonuclease that specifically degrades the RNA of RNA-DNA hybrids. RNase H participates in DNA replication; it helps to specify the origin of genomic replication by suppressing initiation at origins other than the oriC locus; along with the 5'-3' exonuclease of pol1, it removes RNA primers from the Okazaki fragments of lagging strand synthesis; and it defines the origin of replication for ColE1-type plasmids by specific cleavage of an RNA preprimer.[HAMAP-Rule:MF_00042]

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== Publication Abstract from PubMed ==

To obtain more precise insight into the Mg(2+)-binding site essential for RNase HI catalytic activity, we have determined the crystal structure of E. coli RNase HI in complex with Mg2+. The analyzed cocrystal, which is not isomorphous with the Mg(2+)-free crystal previously refined at 1.48 A resolution, was grown at a high MgSO4 concentration more than 100 mM so that even weakly bound Mg2+ sites could be identified. The structure was solved by the molecular replacement method, using the Mg(2+)-free crystal structure as a search model, and was refined to give a final R-value of 0.190 for intensity data from 10 to 2.8 A, using the XPLOR and PROLSQ programs. The backbone structures are in their entirety very similar to each other between the Mg(2+)-bound and the metal-free crystals, except for minor regions in the enzyme interface with the DNA/RNA hybrid. The active center clearly revealed a single Mg2+ atom located at a position almost identical to that previously found by the soaking method. Although the two metal-ion mechanism had been suggested by another group (Yang, W., Hendrickson, W.A., Crouch, R.J., Satow, Y. Science 249:1398-1405, 1990) and partially supported by the crystallographic study of inactive HIV-1 RT RNase H fragment (Davies, J.F., II, Hostomska, Z., Hostomsky, Z., Jordan, S.R., Matthews, D. Science 252:88-95, 1991), the present result excludes the possibility that RNase HI requires two metal-binding sites for activity. In contrast to the features in the metal-free enzyme, the side chains of Asn-44 and Glu-48 are found to form coordinate bonds with Mg2+ in the metal-bound crystal.

Crystal structure of Escherichia coli RNase HI in complex with Mg2+ at 2.8 A resolution: proof for a single Mg(2+)-binding site.,Katayanagi K, Okumura M, Morikawa K Proteins. 1993 Dec;17(4):337-46. PMID:8108376<ref>PMID:8108376</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Bacillus coli migula 1895]]

[[Category: Katayanagi, K]]

[[Category: Morikawa, K]]