title: Salt-tolerant and thermostable glutaminases of cryptococcus species form a new glutaminase family.
abstract: Genes encoding salt-tolerant and thermostable glutaminases were isolated from Cryptococcus species. The glutaminase gene, CngahA, from C. nodaensis NISL-3771 was 2,052 bp in length and encoded a 684-amino acid protein. The gene, CagahA, from C. albidus ATCC20293 was 2,100 bp in length and encoded a 700-amino acid protein. These glutaminases showed 44% identity. By searches on public databases, we found that these glutaminases are not similar to any other characterized glutaminases, but are similar to certain hypothetical proteins. On searching the conserved domain with the basic local alignment search tool (BLAST), it was found that they have the amidase domain and are members of the amidase signature superfamily. They were expressed in Saccharomyces cerevisiae, and their activity was detected on the cell surface. This study revealed that they are a new type of glutaminase with the amidase signature sequence, and that they form a new glutaminase family.
authors: Research and Development Division, Kikkoman Corporation, Noda, Chiba, Japan. koito@mail.kikkoman.co.jp
authors: Kotaro
authors: K
authors: Ito
authors: Genryou
authors: G
authors: Umitsuki
authors: Tetsuya
authors: T
authors: Oguma
authors: Yasuji
authors: Y
authors: Koyama
mesh_terms: D000581:Amidohydrolases / Q000737:chemistry / Q000235:genetics; D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003454:Cryptococcus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005796:Genes; D005972:Glutaminase / Q000032:analysis / Q000235:genetics* / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein / Q000379:methods*
chemical_list: D018076:DNA, Complementary; D000581:Amidohydrolases; D005972:Glutaminase; C477762:salt-tolerant glutaminase; C019665:amidase