CLONING AND NUCLEOTIDE SEQUENCE OF A FULL-LENGTH cDNA ENCODING ASCARIS SUUM PHOSPHOFRUCTOKINASE

• Published in: The Journal of parasitology 2005-06, Vol.91 (3), p.585-590
• Main Authors: Kulkarni, Gopal, Sabnis, Nirupama A, Bhat, Kolari S, Harris, Ben G
• Format: Article
• Language: English
• Subjects: 6-phosphofructokinase; Allosteric properties; Amino Acid Sequence; amino acid sequences; Amino acids; animal parasitic nematodes; Animals; Ascaris suum; Ascaris suum - enzymology; Ascaris suum - genetics; Base Sequence; Binding sites; Biochemistry; Biological and medical sciences; Cloning; Cloning, Molecular; Complementary DNA; Consensus Sequence; Conserved sequence; DNA, Complementary - chemistry; DNA, Helminth - chemistry; E coli; Enzymatic activity; Enzyme activity; Enzymes; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Homology; Humans; Invertebrates; Kinases; Laboratories; Ligands; Mass spectrometry; Mice; Molecular Sequence Data; Molecular Weight; MOLECULAR-CELL BIOLOGY; Mutation; Nematodes; Nucleotide sequence; nucleotide sequences; Nucleotides; Peptides; Pfk gene; Phosphofructokinase; Phosphofructokinase-1 - chemistry; Phosphofructokinase-1 - genetics; Phosphorylation; Plasmids; Proteins; Rabbits; Scientific imaging; Sequence Alignment; sequence analysis; sequence homology; Sequencing; Stop codon; structure-activity relationships; Substrates
• ISSN: 0022-3395; 1937-2345
• DOI: 10.1645/GE-369R

The nucleotide sequence of a full-length cDNA encoding phosphofructokinase (PFK) enzyme from the parasitic nematode Ascaris suum was determined. The entire sequence of 2,653 bases comprises a single open reading frame of 2,452 bases and a noncoding region of 201 bases after the stop codon. The mature protein contains 812 amino acids and has a molecular mass of 90,900 Da. The amino acid sequences of several peptides derived from the purified protein show excellent correspondence with the translated nucleotide sequence. Comparison of the amino acid sequence of the protein with those of 3 other worms as well as those of human, rabbit, and bacterial enzymes reveals highly conserved regions interrupted with stretches of lesser sequence similarity. Analyses of the subunit primary structure reveal, as in other eukaryotic PFKs, that the amino-terminal half is homologous to the carboxy-terminal half, supporting the hypothesis that the PFK gene evolved by duplication of the prokaryotic gene and that the allosteric sites arose by mutations at the catalytic site. The location of the phosphorylation site is unique and different compared with other PFKs and plays a key role in regulation of the enzyme activity. Structural motifs such as the putative substrate and effector binding domains and also the key amino acids involved therein are clearly identified by alignment of all the PFK protein sequences.