The Putative Acetyl-Coa Synthetase Gene of Cryptosporidium parvum and a New Conserved Protein Motif in Acetyl-Coa Synthetases

Abstract

We determined the nucleotide (nt) sequence of the putative gene encoding acetyl-coenzyme A synthetase (ACS) from the parasitic protozoan Cryptosporidium parvum. The gene is single copy, located on a chromosome of approximately 1.08 mb, and has no introns. The gene is characterized by low codon usage bias and encodes a 694-amino acid (aa) protein with a predicted molecular size of 78 kDa, similar to other ACSs from different prokaryotic and eukaryotic species. Comparison of multiple protein alignments of ACSs revealed a new conserved sequence motif PKT(R/V/L)SGK(I/V/T)(T/M/V/K)R(R/N) near the C-terminus, which may be a signature for ACSs. This motif shares significant homology with sequences from other members of the AMP-binding family, has secondary structure similar to the purine-binding motif of ATP- and GTP-ases, and may play a role in the enzymatic activity of proteins from the AMP-binding family.

p-Cymene catabolic pathway in Pseudomonas putida F1: cloning and characterization of DNA encoding conversion of p-cymene to p-cumate

“…These enzymes catalyze a two-step reaction. First, acetate is activated by reaction with ATP, producing an acetyl adenylate intermediate and pyrophosphate; second, coenzyme A displaces the adenylate to yield acetyl coenzyme A. Khramtsov et al (48), in comparing amino acid sequences of fifteen acetyl coenzyme A synthetases, identified two highly conserved motifs (I and II) separated by 289 to 341 amino acids. Both of these are present in all of the acetyl coenzyme A synthetases as well as in other AMP-binding proteins and CymE.…”

“…Motif II is defined as PKT(R/V/L)SGK(I/V/T)(T/M/V/K)R(R/N); in CymE it is amino acid residues 601-PKTRSGKLLRR-611. All of the enzymes that contain motif I are likely to catalyze the formation of an acyl adenylate intermediate, and it has been proposed (4) that this may be the function of this structure, while motif II has similarity to the phosphate-binding P loop of ATPases and GTPases (48,74) and may be involved in the binding of ATP.…”

“…The cymE gene product, presumed to be an acyl coenzyme A synthetase, has a deduced molecular weight of 71,425 (649 amino acids). It is similar to a number of acetyl coenzyme A synthetases, notably those from the cyanobacterium Synechocystis sp., (42% identity in 636 amino acid residues [46]), E. coli (40% identity in 629 amino acid residues [10]), and the parasitic protozoan Cryptosporidium parvum (36% identity in 634 amino acid residues [48]). These enzymes catalyze a two-step reaction.…”

Purification and Properties of Acetyl‐CoA Synthetase (ADP‐forming), an Archaeal Enzyme of Acetate Formation and ATP Synthesis, from the Hyperthermophile Pyrococcus furiosus

“…For example, the enzymes from methanogenic Archaea (Methanothrix species) and from eukaryotes (e.g. Saccharomyces, Penicillium) have native molecular masses of about 140-150 kDa and are homodimers with subunits of about 70-75 kDa or exist as momomeric forms (about 70 kDa) (Jetten et al, 1989;Teh and Zinder, 1992;Frenkel and Kitchens, 1977;Martinez-Blanco et al, 1992;Zeiher and Randall, 1991;Khramtsov et al, 1996). The physiological function of ADPforming acetyl-CoA synthetase is the formation of acetate, whereas AMP-forming synthetases are operative in the activation of acetate to acetyl-CoA (Schafer et al, 1993).…”

Caenorhabditis elegans SUR-5, a Novel but Conserved Protein, Negatively Regulates LET-60 Ras Activity during Vulval Induction

“…SUR-5 protein has a relatively weak but probably significant sequence similarity to acetyl coenzyme A (acetyl-CoA) synthetases (ϳ21 to 24% amino acid identity). At the C terminus of acetyl-CoA synthetases, there is an AMP binding-site consensus (16). Amino acids 658 to 669 of SUR-5, PYTSSGKKVEV, have similarity to the AMP binding site consensus…”