SUC2/YIL162W Summary Help

Standard Name SUC2
Systematic Name YIL162W
Feature Type ORF, Verified
Description Invertase; sucrose hydrolyzing enzyme; a secreted, glycosylated form is regulated by glucose repression, and an intracellular, nonglycosylated enzyme is produced constitutively (1, 2, 3 and see Summary Paragraph)
Name Description SUCrose fermentation
Chromosomal Location
ChrIX:37385 to 38983 | ORF Map | GBrowse
Genetic position: -153 cM
Gene Ontology Annotations All SUC2 GO evidence and references
  View Computational GO annotations for SUC2
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 103 genes
Classical genetics
reduction of function
Large-scale survey
25 total interaction(s) for 25 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 2
  • Affinity Capture-RNA: 1
  • PCA: 3
  • Reconstituted Complex: 1
  • Two-hybrid: 1

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 11
  • Positive Genetic: 4
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 532
Molecular Weight (Da) 60,639
Isoelectric Point (pI) 4.44
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIX:37385 to 38983 | ORF Map | GBrowse
Genetic position: -153 cM
Last Update Coordinates: 1994-12-10 | Sequence: 1994-12-10
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1599 37385..38983 1994-12-10 1994-12-10
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000001424

The S. cerevisiae genome contains seven unlinked loci that encode invertase: SUC1, SUC2, SUC3, SUC4, SUC5, SUC7, and SUC8 (4, 5). This enzyme, also known as "beta-fructofuranosidase," "beta-fructosidase," or "sucrase," plays an important role in sugar metabolism. Invertase catalyzes the hydrolysis of both the disaccharide sucrose (producing the monosaccharides fructose and glucose) and the trisaccharide raffinose (producing fructose and melibiose) (6, 7). All invertase genes except SUC2 are located within telomere sequences (8). Although individual strains may carry any number and combination of SUC genes, the reference strain (S288C) encodes only SUC2 (4) and most recent studies on invertase have focused on that gene.

SUC2 encodes two different forms of invertase, external and internal. External invertase is a highly-glycosylated homodimer that is excreted into the periplasmic space, where the hydrolysis occurs. Only the monosaccharide products of the reaction, glucose and fructose, are transported into the cell. Internal invertase also forms a homodimer, but is not glycosylated and is localized to the cytoplasm (6, 9). Internal invertase has no known function in sucrose fermentation or any other biological process. The two forms of invertase are translated from two distinct, differentially regulated mRNAs, which differ only in their 5'-ends. The 1.9 kb mRNA encodes the external form and specifies a leader peptide which directs the protein product into the secretory pathway. This signal sequence is missing in the 1.8 kb mRNA encoding the internal invertase (2, 10). Although S288C produces both forms of invertase, for technical reasons, only the longer external form is currently represented in SGD.

Internal invertase is synthesized constitutively at low levels, while external invertase is subject to glucose repression (2). Under glucose-repressing conditions, the Mig1p-Cyc8p-Tup1p complex binds directly to the SUC2 promoter, which is packaged into an array of evenly positioned nucleosomes. Several other factors contribute to the repression of SUC2, including Hxk2p (which also binds the SUC2 promoter), Grr1p, Reg1p, Glc7p and Gcr1p. Under inducing conditions, the nucleosomes are remodeled in a SWI/SNF-dependent manner. The SWI/SNF chromatin remodeling complex is necessary for both the initiation and the maintenance of SUC2 transcription (11, 12, 13 and references therein).

Invertase played a notable role in early research on basic enzyme function. The colloquial name "invertase" comes from the fact that a solution of sucrose polarizes light in the opposite direction from an equimolar solution of glucose + fructose. This "inversion" of sugar provided a straightforward functional assay which, along with the easy preparation of a periplasmic protein (14 and references therein), made invertase a popular research subject among early biochemists. Many seminal works defining and describing enzymes, including those of Adrian Brown (15) and Leonor Michaelis and Maude Menton (16), focused on invertase.

Invertase also has a role in the food industry where it is used to produce fructose for use in confectionary. Fructose is often preferred over sucrose in candies with soft centers, as it is sweeter and less prone to crystallization (17).

Last updated: 2007-05-22 Contact SGD

References cited on this page View Complete Literature Guide for SUC2
1) Lutfiyya LL and Johnston M  (1996) Two zinc-finger-containing repressors are responsible for glucose repression of SUC2 expression. Mol Cell Biol 16(9):4790-7
2) Carlson M and Botstein D  (1982) Two differentially regulated mRNAs with different 5' ends encode secreted with intracellular forms of yeast invertase. Cell 28(1):145-54
3) Perlman D, et al.  (1984) Cytoplasmic and secreted Saccharomyces cerevisiae invertase mRNAs encoded by one gene can be differentially or coordinately regulated. Mol Cell Biol 4(9):1682-8
4) Carlson M and Botstein D  (1983) Organization of the SUC gene family in Saccharomyces. Mol Cell Biol 3(3):351-9
5) Naumov GI and Naumova ES  (2010) [Comparative genetics of yeasts: a novel beta-fructosidase gene SUC8 in Saccharomyces cerevisiae] Genetika 46(3):364-72
6) Gascon S, et al.  (1968) Comparative study of the properties of the purified internal and external invertases from yeast. J Biol Chem 243(7):1573-7
7) Taussig R and Carlson M  (1983) Nucleotide sequence of the yeast SUC2 gene for invertase. Nucleic Acids Res 11(6):1943-54
8) Carlson M, et al.  (1985) Evolution of the dispersed SUC gene family of Saccharomyces by rearrangements of chromosome telomeres. Mol Cell Biol 5(11):2894-902
9) Trimble RB and Maley F  (1977) Subunit structure of external invertase from Saccharomyces cerevisiae. J Biol Chem 252(12):4409-12
10) Carlson M, et al.  (1983) The secreted form of invertase in Saccharomyces cerevisiae is synthesized from mRNA encoding a signal sequence. Mol Cell Biol 3(3):439-47
11) Trumbly RJ  (1992) Glucose repression in the yeast Saccharomyces cerevisiae. Mol Microbiol 6(1):15-21
12) Turkel S, et al.  (2003) Mutations in GCR1 affect SUC2 gene expression in Saccharomyces cerevisiae. Mol Genet Genomics 268(6):825-31
13) Geng F and Laurent BC  (2004) Roles of SWI/SNF and HATs throughout the dynamic transcription of a yeast glucose-repressible gene. EMBO J 23(1):127-37
14) O'Sullivan C and Tompson F  (1890) LX.-Invertase: a contribution to the history of an enzyme or unorganised ferment J Chem Soc Trans 57:834-931
15) Brown A  (1902) Enzyme action J Chem Soc Trans 81:373-388
16) Michaelis L and Menten M  (1913) Kinetik der Invertinwirkung Biochem Z 49:333-369
17) Smith J and Hong-Shum L  (2003) Food Additives Data Book :432