Activities | Families | Sequences | Fold types | References | Help
B6db references: 8206881

type Journal Article
authors Tanaka, T.; Yamamoto, S.; Moriya, T.; Taniguchi, M.; Hayashi, H.; Kagamiyama, H.; Oi, S.
title Aspartate aminotransferase from a thermophilic formate-utilizing methanogen, Methanobacterium thermoformicicum strain SF-4: relation to serine and phosphoserine aminotransferases, but not to the aspartate aminotransferase family
journal J Biochem (Tokyo)
Activity 2.6.1.1
sel selected
ui 8206881
year (1994)
volume 115
number 2
pages 309-17
 
keywords Amino Acid Sequence
abstract The primary structure of the aspartate aminotransferase (AspAT) of an archaebacterium, Methanobacterium thermoformicicum strain SF-4, has been determined by cloning and sequencing of the gene for the enzyme. The gene had a consensus promoter and a ribosome binding sequence of methanogens in the 5' untranslated region, followed by an open reading frame starting with ATG and terminating with TGA. The deduced amino acid sequence was identical with the partial amino acid sequences of the enzyme including the N-terminal sequence, and the deduced molecular weight of 41,684 was virtually identical to that reported earlier for this enzyme [Tanaka, T., Yamamoto, S., Taniguchi, M., Hayashi, H., Kuramitsu, S., Kagamiyama, H., & Oi, S. (1992) J. Biochem. 112, 811- 815]. The gene was expressed in Escherichia coli by inserting it into an expression vector just downstream of the lacZ promoter, and this verified that the cloned gene really encodes the Methanobacterium AspAT. The primary structure of the Methanobacterium AspAT showed extremely low homology, 5%, with AspATs of eubacteria, eukaryotes, and a thermoacidophilic arachaebacterium, Sulfolobus solfataricus. On the other hand, the Methanobacterium AspAT showed remarkable amino acid sequence homology, 31.5%, with rat serine:pyruvate aminotransferase and, 13.5%, with E. coli phosphoserine aminotransferase. Thus, the Methanobacterium AspAT apparently belongs to subgroup IV of the aminotransferases [Mehta, P.K., Hale, T.I., & Christen, P. (1993) Eur. J. Biochem. 214, 549-561], but not to subgroup I, in which all the AspATs known so far are included.
last changed 2009/02/17 12:12

B6db references