1f4m

<table><tr><td colspan='2'>[[1f4m]] is a 6 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=1F4M OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1F4M FirstGlance]. <br>

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

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1f4n|1f4n]], [[1rop|1rop]], [[1gto|1gto]], [[1nkd|1nkd]], [[1rpo|1rpo]], [[1b6q|1b6q]], [[1rpr|1rpr]]</div></td></tr>

[[https://www.uniprot.org/uniprot/ROP_ECOLX ROP_ECOLX]] Regulates plasmid DNA replication by modulating the initiation of transcription of the primer RNA precursor. Processing of the precursor of the primer, RNAII, is inhibited by hydrogen bonding of RNAII to its complementary sequence in RNAI. ROP increases the affinity of RNAI for RNAII and thus decreases the rate of replication initiation events.

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== Publication Abstract from PubMed ==

BACKGROUND: Rop is an RNA binding, dimeric, four-helix bundle protein with a well-defined, regular hydrophobic core ideally suited for redesign studies. A family of Rop variants in which the hydrophobic core was systematically redesigned has previously been created and characterized. RESULTS: We present a structural and thermodynamic analysis of Ala2Ile2-6, a variant of Rop with an extensively redesigned hydrophobic core. The structure of Ala2Ile2-6 reveals a completely new fold formed by a conformational "flip" of the two protomers around the dimeric interface. The free-energy profile of Ala2Ile2-6 is also very different from that of wild-type Rop. Ala2Ile2-6 has a higher melting temperature than Rop, but undergoes a slightly smaller free-energy change on unfolding. CONCLUSIONS: The structure of Ala2Ile2-6, along with molecular modeling results, demonstrate the importance of tight packing of core residues and the adoption of favorable core side chain rotamer values in determining helix-helix interactions in the four-helix bundle fold. Structural disorder at the N and C termini of Ala2Ile2-6 provides a basis for the large differences in the enthalpy and entropy of Ala2Ile2-6 folding compared with wildtype Rop.

Dramatic structural and thermodynamic consequences of repacking a protein's hydrophobic core.,Willis MA, Bishop B, Regan L, Brunger AT Structure. 2000 Dec 15;8(12):1319-28. PMID:11188696<ref>PMID:11188696</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: Bishop, B]]

[[Category: Brunger, A T]]

[[Category: Regan, L]]

[[Category: Willis, M A]]

[[Category: Transcription regulation]]