IRR1/YIL026C Summary Help

Standard Name IRR1 1
Systematic Name YIL026C
Alias SCC3 2
Feature Type ORF, Verified
Description Subunit of the cohesin complex; which is required for sister chromatid cohesion during mitosis and meiosis and interacts with centromeres and chromosome arms; relocalizes to the cytosol in response to hypoxia; essential for viability (2, 3, 4 and see Summary Paragraph)
Name Description IRRegular cell behavior 1
Chromosomal Location
ChrIX:307929 to 304477 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All IRR1 GO evidence and references
  View Computational GO annotations for IRR1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 5 genes
Classical genetics
Large-scale survey
reduction of function
57 total interaction(s) for 28 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 21
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 17
  • Biochemical Activity: 1
  • FRET: 3
  • Two-hybrid: 2

Genetic Interactions
  • Dosage Lethality: 1
  • Dosage Rescue: 3
  • Negative Genetic: 1
  • Phenotypic Enhancement: 1
  • Positive Genetic: 1
  • Synthetic Growth Defect: 1
  • Synthetic Lethality: 1
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 1,150
Molecular Weight (Da) 133,007
Isoelectric Point (pI) 4.84
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIX:307929 to 304477 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1994-12-10
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..3453 307929..304477 2011-02-03 1994-12-10
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000001288

IRR1 is an essential gene that encodes a subunit of the yeast cohesin complex, which is required for sister chromatid cohesion in mitosis and meiosis (3, 2, 5, 6, 7). The yeast cohesin complex includes Smc1p and Smc3p, two members of a conserved family of chromosomal ATPases, and Mcd1p (8, 9, 2, 6, 7). Cohesin associates with centromeres and other discrete sites along chromosome arms prior to metaphase; the association with centromeres requires the centromere protein Mif2p, the centromere binding complex CBF3, and Cse4p (10, 11, 12). Scc2p is not a stoichiometric cohesin subunit, but is required for the cohesin complex to associate with chromosomes (2).

Temperature-sensitive mutations in IRR1 cause premature dissociation of sister chromatids (2). Reduced expression of IRR1 alters colony morphology and causes defects in zygote formation and spore germination (1).

Cohesin complexes have been identified in other eukaryotes, including Xenopus, C. elegans, S. pombe, and human (6); proteins similar to Irr1p have been found in mouse, Drosophila, C. elegans, and S. pombe (2).

Last updated: 2000-05-05 Contact SGD

References cited on this page View Complete Literature Guide for IRR1
1) Kurlandzka A, et al.  (1999) Saccharomyces cerevisiae IRR1 protein is indirectly involved in colony formation. Yeast 15(1):23-33
2) Toth A, et al.  (1999) Yeast cohesin complex requires a conserved protein, Eco1p(Ctf7), to establish cohesion between sister chromatids during DNA replication. Genes Dev 13(3):320-33
3) Kurlandzka A, et al.  (1995) A new essential gene located on Saccharomyces cerevisiae chromosome IX. Yeast 11(9):885-90
4) Ghosh Dastidar R, et al.  (2012) The nuclear localization of SWI/SNF proteins is subjected to oxygen regulation. Cell Biosci 2(1):30
5) Klein F, et al.  (1999) A central role for cohesins in sister chromatid cohesion, formation of axial elements, and recombination during yeast meiosis. Cell 98(1):91-103
6) Hirano T  (1999) SMC-mediated chromosome mechanics: a conserved scheme from bacteria to vertebrates? Genes Dev 13(1):11-9
7) Strunnikov AV and Jessberger R  (1999) Structural maintenance of chromosomes (SMC) proteins: conserved molecular properties for multiple biological functions. Eur J Biochem 263(1):6-13
8) Michaelis C, et al.  (1997) Cohesins: chromosomal proteins that prevent premature separation of sister chromatids. Cell 91(1):35-45
9) Guacci V, et al.  (1997) A direct link between sister chromatid cohesion and chromosome condensation revealed through the analysis of MCD1 in S. cerevisiae. Cell 91(1):47-57
10) Tanaka T, et al.  (1999) Identification of cohesin association sites at centromeres and along chromosome arms. Cell 98(6):847-58
11) Blat Y and Kleckner N  (1999) Cohesins bind to preferential sites along yeast chromosome III, with differential regulation along arms versus the centric region. Cell 98(2):249-59
12) Megee PC, et al.  (1999) The centromeric sister chromatid cohesion site directs Mcd1p binding to adjacent sequences. Mol Cell 4(3):445-50