当前位置： SCI文献检索 > JOURNAL OF BACTERIOLOGY期刊下所有文献 > Molecular characterization of the alpha-glucosidase gene (malA) from the hyperthermophilic archaeon Sulfolobus solfataricus.

Molecular characterization of the alpha-glucosidase gene (malA) from the hyperthermophilic archaeon Sulfolobus solfataricus.

Abstract：

:Acidic hot springs are colonized by a diversity of hyperthermophilic organisms requiring extremes of temperature and pH for growth. To clarify how carbohydrates are consumed in such locations, the structural gene (malA) encoding the major soluble alpha-glucosidase (maltase) and flanking sequences from Sulfolobus solfataricus were cloned and characterized. This is the first report of an alpha-glucosidase gene from the archaeal domain. malA is 2,083 bp and encodes a protein of 693 amino acids with a calculated mass of 80.5 kDa. It is flanked on the 5' side by an unusual 1-kb intergenic region. Northern blot analysis of the malA region identified transcripts for malA and an upstream open reading frame located 5' to the 1-kb intergenic region. The malA transcription start site was located by primer extension analysis to a guanine residue 8 bp 5' of the malA start codon. Gel mobility shift analysis of the malA promoter region suggests that sequences 3' to position -33, including a consensus archaeal TATA box, play an essential role in malA expression. malA homologs were detected by Southern blot analysis in other S. solfataricus strains and in Sulfolobus shibatae, while no homologs were evident in Sulfolobus acidocaldarius, lending further support to the proposed revision of the genus Sulfolobus. Phylogenetic analyses indicate that the closest S. solfataricus alpha-glucosidase homologs are of mammalian origin. Characterization of the recombinant enzyme purified from Escherichia coli revealed differences from the natural enzyme in thermostability and electrophoretic behavior. Glycogen is a substrate for the recombinant enzyme. Unlike maltose hydrolysis, glycogen hydrolysis is optimal at the intracellular pH of the organism. These results indicate a unique role for the S. solfataricus alpha-glucosidase in carbohydrate metabolism.

journal_name

J Bacteriol

journal_title

Journal of bacteriology

authors

Rolfsmeier M,Haseltine C,Bini E,Clark A,Blum P

doi

10.1128/JB.180.5.1287-1295.1998

subject

Has Abstract

pub_date

1998-03-01 00:00:00

pages

1287-95

issue

eissn

0021-9193

issn

1098-5530

journal_volume

180

pub_type

杂志文章

在线工具

Molecular characterization of the alpha-glucosidase gene (malA) from the hyperthermophilic archaeon Sulfolobus solfataricus.