Novel biochemical properties of a CRP/FNR family transcription factor from Mycobacterium tuberculosis.
Cyclic AMP (cAMP) receptor protein (CRP)/fumarate nitrate reductase regulator (FNR) family proteins are actively associated with defense against low oxygen stress, starvation and extreme temperature conditions. They are DNA-binding proteins and regulate target genes carrying the regulatory CRP/FNR cognate nucleotide sequence elements. Recombinant protein encoded by the Mycobacterium tuberculosis ORF Rv3676, a putative CRP/FNR regulator, was purified from Escherichia coli and was found to exist as dimer, devoid of any metal cation cofactor. Purified rRv3676 exhibited cAMP binding in a concentration-dependent manner. At lower concentrations of cAMP (6-10 microM) rRv3676 shows positive cooperativity; at 10 microM cAMP the protein exists in the most open conformation. rRv3676 could bind specifically to the putative CRP/FNR nucleotide sequence elements as evident from electrophoretic mobility shift assay.
Akhter
Yusuf
Y
Laboratory of Molecular and Cellular Biology, CDFD, Hyderabad 500076, India.
Tundup
Smanla
S
Hasnain
Seyed E
SE
D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites; D003067:Coenzymes / Q000032:analysis; D000242:Cyclic AMP / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism; D019281:Dimerization; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000235:genetics; D008670:Metals / Q000032:analysis; D009169:Mycobacterium tuberculosis / Q000502:physiology*; D011485:Protein Binding; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D001426:Bacterial Proteins; C513697:CRP protein, Mycobacterium tuberculosis; D003067:Coenzymes; D004269:DNA, Bacterial; D008670:Metals; D011994:Recombinant Proteins; D014157:Transcription Factors; D000242:Cyclic AMP