1rba

<table><tr><td colspan='2'>[[1rba]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/"dicrospirillum_rubrum"_enderlein_1925 "dicrospirillum rubrum" enderlein 1925]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RBA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1RBA FirstGlance]. <br>

</td></tr><tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Ribulose-bisphosphate_carboxylase Ribulose-bisphosphate carboxylase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.39 4.1.1.39] </span></td></tr>

[[https://www.uniprot.org/uniprot/RBL2_RHORU RBL2_RHORU]] RuBisCO catalyzes two reactions: the carboxylation of D-ribulose 1,5-bisphosphate, the primary event in carbon dioxide fixation, as well as the oxidative fragmentation of the pentose substrate. Both reactions occur simultaneously and in competition at the same active site.[HAMAP-Rule:MF_01339]

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== Publication Abstract from PubMed ==

The crystal structure of a mutant of ribulose bisphosphate carboxylase/oxygenase from Rhodospirillium rubrum, where Asp193, one of the ligands of the magnesium ion at the activator site, is replaced by Asn, has been determined to a nominal resolution of 0.26 nm. The mutation of Asp to Asn induces both local and global conformation changes as follows. The side chain of Asn193 moves away from the active site and interacts with main-chain oxygen of residue 165, located in the neighbouring strand beta 1 of the alpha/beta barrel. The side chain of Lys166, which forms a salt bridge with Asp193 in the wild-type enzyme, interacts with Asn54 from the second subunit and creates a new subunit-subunit interaction. Another new subunit-subunit interaction is formed, more than 1.2 nm away from the site of the mutation. In the mutant enzyme, the side chain of Asp263 interacts with the side chain of Thr106 from the second subunit. Asp193 is not part of a subunit-subunit interface area or an allosteric regulatory site. Nevertheless, replacement of this residue by Asn results, unexpectedly, in a difference in the packing of the two subunits, which can be described as a slight rotation of one of the subunits relative to the second. The observed structural changes at the active site of the enzyme provide a molecular explanation for the differing behaviour of the Asp193----Asn mutant with respect to activation.

Substitution of ASP193 to ASN at the active site of ribulose-1,5-bisphosphate carboxylase results in conformational changes.,Soderlind E, Schneider G, Gutteridge S Eur J Biochem. 1992 Jun 15;206(3):729-35. PMID:1606957<ref>PMID:1606957</ref>

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

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== References ==

<references/>

[[Category: Dicrospirillum rubrum enderlein 1925]]

[[Category: Ribulose-bisphosphate carboxylase]]

[[Category: Schneider, G]]

[[Category: Soderlind, E]]