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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1994-3-10
pubmed:databankReference
pubmed:abstractText
The enzymatic hydrolysis of starch, consisting of linear (amylose) and branched (amylopectin) glucose polymers, is catalyzed by alpha-, beta- and glucoamylases (gamma-amylases), cyclodextrinases, alpha-glucosidases, and debranching enzymes. Saccharomyces cerevisiae cannot utilize starch. Our laboratory has previously co-expressed the Bacillus amyloliquefaciens alpha-amylase (AMY) and the Saccharomyces diastaticus glucoamylase (STA2) genes in S. cerevisiae. A gene encoding a debranching enzyme (pullulanase) from Klebsiella pneumoniae ATCC15050 was cloned and its nucleotide sequence determined. This gene will be co-expressed with the alpha- and gamma-amylase to produce an amylolytic S. cerevisiae strain. Extensive data base comparisons of the K. pneumoniae pullulanase amino-acid sequence with the amino-acid sequences of other debranching enzymes and alpha-, beta- and gamma-amylases (from bacteria, yeasts, higher fungi and higher eukaryotes), indicated that these debranching enzymes have amino-acid regions similar to those found in alpha-amylases. The conserved regions in alpha-amylases comprise key residues that are implicated in substrate binding, catalysis, and calcium binding and are as follows. Region 1: DVVINH; region 2: GFRLDAAKH and region 4: FVDNHD. When comparing conserved regions, no similarity could be detected between debranching enzymes and beta- and gamma-amylases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0172-8083
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:geneSymbol
pulA
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
400-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Regional sequence homologies in starch-degrading enzymes.
pubmed:affiliation
Department of Microbiology, University of Stellenbosch, South Africa.
pubmed:publicationType
Journal Article