A0A2V0R8Q9 · LSCB_PSESF

Function

function

Catalyzes the synthesis of levan, a fructose polymer, by transferring the fructosyl moiety from sucrose to a growing acceptor molecule (PubMed:33675829).
Also displays sucrose hydrolase activity (PubMed:33675829).

Miscellaneous

Strain KL103 contains two functional levansucrases, Lscbeta and Lscgamma (PubMed:33675829).
A third copy, lscalpha, is non-coding because of a premature stop codon (PubMed:33675829).
Lscbeta and Lscgamma show different sucrose splitting and polymerization properties, and differential expression, suggesting two distinct roles in the physiology of the bacterium (PubMed:33675829).

Catalytic activity

Activity regulation

Sucrose hydrolase activity is negatively affected by salt concentration (PubMed:33675829).
The levan polymerization rate is constant regardless of sucrose concentration (PubMed:33675829).

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
54.1 mMsucrose5.0
100.1 mMsucrose7.0
kcat is 8500 min-1 with sucrose as substrate (at pH 5.0). kcat is 15000 min-1 with sucrose as substrate (at pH 7.0).

pH Dependence

For sucrose hydrolase activity, shows the maximal activity in the 5-7 pH range, while the activity decreases at pH values lower that 5 and higher than 8 (PubMed:33675829).
Levan polymerization occurs mainly at pH 5.0 (PubMed:33675829).

Temperature Dependence

Highly thermostable (PubMed:33675829).
At pH 5.0, sucrose hydrolase activity progressively increases with temperature until 55 degrees Celsius and then falls quickly (PubMed:33675829).
At ph 7.0, the sucrose hydrolase activity increases rapidly passing from 4 to 15 degrees Celsius and remains constant up to 55 degrees Celsius (PubMed:33675829).

Features

Showing features for binding site, active site, site.

TypeIDPosition(s)Description
Binding site61sucrose (UniProtKB | ChEBI)
Active site62Nucleophile
Binding site62sucrose (UniProtKB | ChEBI)
Binding site148sucrose (UniProtKB | ChEBI)
Binding site218sucrose (UniProtKB | ChEBI)
Binding site219sucrose (UniProtKB | ChEBI)
Site219Transition state stabilizer
Active site303Proton donor/acceptor

GO annotations

AspectTerm
Molecular Functionlevansucrase activity
Biological Processcarbohydrate utilization

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Levansucrase Lscbeta
  • EC number
  • Alternative names
    • Sucrose 6-fructosyltransferase

Gene names

    • Name
      lscbeta
    • ORF names
      KPSA3_07534

Organism names

Accessions

  • Primary accession
    A0A2V0R8Q9

Proteomes

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004597481-431Levansucrase Lscbeta

Expression

Induction

Highly expressed at the end of the exponential phase of growth.

Interaction

Subunit

Homodimer.

Family & Domains

Sequence similarities

Belongs to the glycosyl hydrolase 68 family.

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    431
  • Mass (Da)
    47,675
  • Last updated
    2018-09-12 v1
  • Checksum
    6718E045E08B57EB
MSTSSSALSQLKNSPLAGNINYEPTVWSRADALKVNENDPTTTQPLVSADFPVMSDTVFIWDTMPLRELDGTVVSVNGWSVILTLTADRHPDDPQYLDANGRYDIKRDWEDRHGRARMCYWYSRTGKDWIFGGRVMAEGVSPTTREWAGTPILLNDKGDIDLYYTCVTPGAAIAKVRGRIVTSDQGVELKDFTQVKKLFEADGTYYQTEAQNSSWNFRDPSPFIDPNDGKLYMVFEGNVAGERGSHTVGAAELGPVPPGHEDVGGARFQVGCIGLAVAKDLSGEEWEILPPLVTAVGVNDQTERPHYIFQDGKYYLFTISHKFTYAEGLEGPDGVYGFVGEHLFGPYRPMNASGLVLGNPPEQPFQTYSHCVMPNGLVTSFIDSVPTDGEDYRIGGTEAPTVRIVLKGDRSFVQEEYDYGYIPAMKDVQLS

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
BGKA01000296
EMBL· GenBank· DDBJ
GBH21487.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp