1am2

<table><tr><td colspan='2'>[[1am2]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"mycobacterium_xenopei"_(sic)_schwabacher_1959 "mycobacterium xenopei" (sic) schwabacher 1959]. The November 2010 RCSB PDB [http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Inteins'' by David Goodsell is [http://dx.doi.org/10.2210/rcsb_pdb/mom_2010_11 10.2210/rcsb_pdb/mom_2010_11]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AM2 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1AM2 FirstGlance]. <br>

</td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">RTP ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1789 "Mycobacterium xenopei" (sic) Schwabacher 1959])</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1am2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1am2 OCA], [http://pdbe.org/1am2 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1am2 RCSB], [http://www.ebi.ac.uk/pdbsum/1am2 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1am2 ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/GYRA_MYCXE GYRA_MYCXE]] DNA gyrase negatively supercoils closed circular double-stranded DNA in an ATP-dependent manner and also catalyzes the interconversion of other topological isomers of double-stranded DNA rings, including catenanes and knotted rings (By similarity).

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== Publication Abstract from PubMed ==

Several genes from prokaryotes and lower eukaryotes have been found to contain an in-frame open reading frame, which encodes for an internal protein (intein). Post-translationally, the internal polypeptide auto-splices and ligates the external sequences to yield a functional external protein (extein) and an intein. Most, but not all inteins, contain, apart from a splicing domain, a separate endonucleolytic domain that enables them to maintain their presence by a homing mechanism. We report here the crystal structure of an intein found in the gyrase A subunit from Mycobacterium xenopi at 2.2 A resolution. The structure contains an unusual beta-fold with the catalytic splice junctions at the ends of two adjacent antiparallel beta-strands. The arrangement of the active site residues Ser 1, Thr 72, His 75, His 197, and Asn 198 is consistent with a four-step mechanism for the cleavage-ligation reaction. Using site-directed mutagenesis, the N-terminal cysteine, proposed as the nucleophile in the first step of the splicing reaction, was changed to a Ser 1 and Ala 0, thus capturing the intein in a pre-spliced state.

Crystal structure of GyrA intein from Mycobacterium xenopi reveals structural basis of protein splicing.,Klabunde T, Sharma S, Telenti A, Jacobs WR Jr, Sacchettini JC Nat Struct Biol. 1998 Jan;5(1):31-6. PMID:9437427<ref>PMID:9437427</ref>

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

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== References ==

<references/>

[[Category: Klabunde, T]]

[[Category: Sacchettini, J C]]

[[Category: Sharma, S]]

[[Category: Protein splicing]]