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The Corrin Moiety of Coenzyme B 12 is the Determinant for Switching the btuB Riboswitch of E. coli
Author(s) -
Gallo Sofia,
Oberhuber Michael,
Sigel Roland K. O.,
Kräutler Bernhard
Publication year - 2008
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200800099
Subject(s) - riboswitch , corrin , rna , chemistry , biochemistry , biology , gene , non coding rna , vitamin b12
Abstract Riboswitches are regulatory elements in the 5′‐untranslated region (5′‐UTR) of bacterial mRNAs that bind certain metabolites with high specificity and affinity. The 202 nucleotide (nt)‐long btuB riboswitch RNA of E. coli interacts specifically with coenzyme B 12 and its derivatives thereby leading to changes in the RNA structure and hence to an altered expression of the downstream btuB gene. We report the investigations of the rearrangement of the three‐dimensional structure of the btuB riboswitch upon binding to four different B 12 derivatives: coenzyme B 12 , vitamin B 12 , adenosyl factor A and adenosyl‐cobinamide. In‐line probing experiments have shown that the corrin ring plays the crucial role in switching the three‐dimensional riboswitch structure. Instead, the apical ligands influence only the binding affinity of the B 12 derivative to the btuB riboswitch.