Disease relevance of selD

• The selD gene from Escherichia coli, whose product is involved in selenium metabolism, has been cloned and sequenced. selD codes for a protein of 347 amino acids with a calculated molecular weight of 36,687 [1].
• Analysis of the selD gene product through expression of the gene in the phage T7 promoter/polymerase system confirmed the predicted molecular weight of the protein [1].

High impact information on selD

• Furthermore, purified recombinant SepSecS converts Sep-tRNA(Sec) into Sec-tRNA(Sec) in vitro in the presence of sodium selenite and purified recombinant E. coli selenophosphate synthetase (SelD) [2].
• Inactivation of the selD gene prevented synthesis of selenophosphate, the reactive selenium donor, required for the specific incorporation pathway [3].
• As expected, the double mutant strain, RL165 Delta selD, when grown anaerobically in LB + glucose medium containing (75)SeO(3)(2-), failed to synthesize selenium-dependent formate dehydrogenase H and seleno-tRNAs [3].
• Selenophosphate synthetase, the Escherichia coli selD gene product, is a 37-kDa protein that catalyzes the synthesis of selenophosphate from ATP and selenide [4].
• A novel gene detected in mouse embryonic sites of hematopoiesis was cloned and shown to be a eukaryotic analog of the Escherichia coli selenophosphate synthetase gene [5].

Chemical compound and disease context of selD

• To investigate the biological activity of the sps2 gene product in vivo, the mutated sps2 gene, which contains cysteine in the place of the TGA encoded selenocysteine in the wild type, was expressed in the E. coli selD deficient mutant, MB08 [6].
• Biochemical analysis of Escherichia coli selenophosphate synthetase mutants. Lysine 20 is essential for catalytic activity and cysteine 17/19 for 8-azido-ATP derivatization [7].

Biological context of selD

• The biological activities of the wild type and mutant proteins were studied using E. coli MB08 (selD-) transformed with plasmids containing the selD genes [8].
• The products of the orf183 and topB genes were required neither for selenoprotein biosynthesis nor for selenation of tRNAs. selAB transcription was driven by a single, weak promoter; however, two major selD operon transcripts were identified [9].
• The open reading frame located downstream of R. capsulatus putR exhibited strong homology to the E. coli selD gene, which is involved in selenium metabolism [10].
• R. capsulatus selD mutants exhibited a Put+ phenotype, demonstrating that selD is required neither for viability nor for proline utilization [10].

Associations of selD with chemical compounds

• These data together with the finding that selenophosphate synthetase is highly specific for selenide indicate that the phosphate moiety of selenophosphate provides selenocysteine synthase with the discrimination specificity against sulfur [11].
• However, replacement of Cys with either Ala, Ser, or Thr resulted in a loss of ability to complement the selD mutation [6].

Other interactions of selD

• Efficient formation of selenocysteinyl-tRNA(Ser)(UCA) was achieved by using extracts in which both the selD and the selA gene products were overproduced [1].
• DNA sequence analysis of this region revealed three open reading frames designated selD, putR, and putA [10].
• One of these genes, ybbB, is frequently found within bacterial operons that contain selD, the selenophosphate synthetase gene, suggesting a role in selenium metabolism [12].

Analytical, diagnostic and therapeutic context of selD

• With antibodies elicited to E. coli selenophosphate synthetase the enzyme was detected in extracts of rat brain, liver, kidney, and lung by immunoblotting [13].

References