Ramakrishnan Balasubramanian

Learn More
Previous studies have shown that the transcriptional coactivator protein Gcn5 functions as a catalytic histone acetyltransferase (HAT). In this work, we examine the roles of the Ada2 and Ada3 coactivator proteins that are functionally linked to Gcn5. We show that yeast Ada2, Ada3, and Gcn5 form a catalytic core of the ADA and Spt-Ada-Gcn5-acetyltransferase(More)
The physical basis for the natural evolution of a primitive decoding system is presented using the concepts of molecular interactions. Oligoribonucleotides of five residues havingU at the 5′-end, a purine at the 3′-end and any combination of three bases in the middle is taken as a primitive tRNA (PIT). From conformational considerations PIT is expected to(More)
The suf operon is composed of four genes (sufB, sufC, sufD, and sufS) and is highly conserved in the genomes of cyanobacteria. Open reading frame sll0088 in Synechocystis sp. strain PCC 6803 is located near the 5' end of the suf operon but is transcribed in the direction opposite that of the suf operon. We previously reported the isolation of two(More)
Vast world reserves of methane gas are underutilized as a feedstock for the production of liquid fuels and chemicals owing to the lack of economical and sustainable strategies for the selective oxidation of methane to methanol. Current processes to activate the strong C-H bond (104 kcal mol(-1)) in methane require high temperatures, are costly and(More)
Methanobactin (Mb), a 1217-Da copper chelator produced by the methanotroph Methylosinus trichosporium OB3b, is hypothesized to mediate copper acquisition from the environment, particularly from insoluble copper mineral sources. Although indirect evidence suggests that Mb provides copper for the regulation and activity of methane monooxygenase enzymes,(More)
Copper plays a key role in the physiology of methanotrophs. One way that these bacteria meet their high copper requirement is by the biosynthesis and release of high affinity copper binding compounds called methanobactins. Recent advances in methanobactin characterization include the first crystal structure, detailed spectroscopic analyses, and studies of(More)
The sufR gene encodes a protein that functions as a transcriptional repressor of the suf regulon in cyanobacteria. It is predicted to contain an N-terminal helix loop helix DNA binding motif and a C-terminal Fe/S binding domain. Through immunoblotting assays of cell extracts, the sufR product in Synechocystis sp. PCC 6803 was shown to have a mass of(More)
SufA, IscA, and Nfu have been proposed to function as scaffolds in the assembly of Fe/S clusters in bacteria. To investigate the roles of these proteins further, single and double null-mutant strains of Synechococcus sp. strain PCC 7002 were constructed by insertional inactivation of genes homologous to sufA, iscA, and nfu. Demonstrating the nonessential(More)
Chemical rescue of site-modified amino acids using externally supplied organic molecules represents a powerful method to investigate structure-function relationships in proteins. Here we provide definitive evidence that aryl and alkyl thiolates, reagents typically used for in vitro iron-sulfur cluster reconstitutions, serve as rescue ligands to a(More)