[Cloning and characterization of two beta-mannosidase cDNAs in Gossypium hirsutum L].
By using the method of PCR-based cDNA library screening, two beta-mannosidase clones, GhManA1 and GhManA2, had been isolated. GhManA1 had a length of 2692 bp coding for a polypeptide of 834 amino acids, and GhManA2 was 3209 bp which encoded a polypeptide of 976 amino acids. GhManA1 and GhManA2 shared an identical sequence of 747 amino acids in their carboxyl-terminals, but were distinctly different in their amino-terminals. Both beta-mannosidases were members of glycosyl hydrolase family 2, which had two conserved glutamine residues in their sequences as the acid-base catalyst and nucleophilic group, respectively. Most surprisingly, the first 93 amino acids in the amino-terminal of GhManA1 was highly homologous to the beta-barrel domain of ATP synthase alpha-/beta-subunit, but an analogous domain has never been found in the sequence of other non-ATP synthase protein. GhManA1 was constitutively expressed in different cotton tissues, and GhManA2 was specifically expressed in fiber cells.
Jiang
Jian-Xiong
JX
Cotton Research Institute, National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
Guo
Wang-Zhen
WZ
Zhang
Tian-Zhen
TZ
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D003368:Gossypium / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D044902:beta-Mannosidase / Q000737:chemistry / Q000235:genetics*
D018076:DNA, Complementary; D044902:beta-Mannosidase