BRN1/YBL097W Summary Help

Standard Name BRN1 1, 2
Systematic Name YBL097W
Feature Type ORF, Verified
Description Subunit of the condensin complex; required for chromosome condensation and for clustering of tRNA genes at the nucleolus; may influence multiple aspects of chromosome transmission (1, 3, 4 and see Summary Paragraph)
Name Description homolog of BaRreN 1
Chromosomal Location
ChrII:40831 to 43095 | ORF Map | GBrowse
Gene Ontology Annotations All BRN1 GO evidence and references
  View Computational GO annotations for BRN1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 3 genes
Classical genetics
Large-scale survey
reduction of function
50 total interaction(s) for 37 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 20
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 4
  • Co-localization: 1
  • Two-hybrid: 1

Genetic Interactions
  • Dosage Lethality: 1
  • Dosage Rescue: 1
  • Negative Genetic: 1
  • Phenotypic Suppression: 1
  • Synthetic Lethality: 19

Expression Summary
Length (a.a.) 754
Molecular Weight (Da) 86,216
Isoelectric Point (pI) 4.33
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrII:40831 to 43095 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 2011-02-03
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..2265 40831..43095 2011-02-03 2011-02-03
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 SGDIDS000000193

BRN1 is an essential gene that encodes the yeast homolog of Drosophila Barren and Xenopus XCAP-H (5, 6, 7, 8, 2, 1). XCAP-H is a component of the condensin complex, a complex originally identified in Xenopus egg extracts that is required for chromosome condensation (6, 8, 7). Condensin complexes have been identified in many eukaryotes (8, 7); in addition to Barren and XCAP-H, Brn1p homologs include human BRRN1, mouse BRRN1, S. pombe Cnd2, and a predicted protein in Arabidopsis (7, 2). Smc2p, Smc4p, Ycg1p and Ycs4p are the other yeast condensin subunits (7, 2); overexpression of YCG1, but not SMC2, suppresses brn1 temperature-sensitive mutations (2). Temperature-sensitive brn1 mutants show defects in chromosome condensation and segregation, and some brn1 mutations cause cells to arrest growth in S phase (2, 1). Sister chromatid cohesion appears normal in brn1 mutants (2). Although the Drosophila Barren protein interacts physically with, and may regulate, topoisomerase II (5), the phenotypes of yeast brn1 mutants do not resemble those of top2 mutants, suggesting that in yeast Brn1p is not an essential regulator of topoisomerase II activity (1).

Last updated: 2000-04-20 Contact SGD

References cited on this page View Complete Literature Guide for BRN1
1) Lavoie BD, et al.  (2000) Mitotic chromosome condensation requires Brn1p, the yeast homologue of Barren. Mol Biol Cell 11(4):1293-304
2) Ouspenski II, et al.  (2000) Chromosome condensation factor Brn1p is required for chromatid separation in mitosis. Mol Biol Cell 11(4):1305-13
3) Freeman L, et al.  (2000) The condensin complex governs chromosome condensation and mitotic transmission of rDNA. J Cell Biol 149(4):811-24
4) Haeusler RA, et al.  (2008) Clustering of yeast tRNA genes is mediated by specific association of condensin with tRNA gene transcription complexes. Genes Dev 22(16):2204-14
5) Bhat MA, et al.  (1996) Chromatid segregation at anaphase requires the barren product, a novel chromosome-associated protein that interacts with Topoisomerase II. Cell 87(6):1103-14
6) Hirano T, et al.  (1997) Condensins, chromosome condensation protein complexes containing XCAP-C, XCAP-E and a Xenopus homolog of the Drosophila Barren protein. Cell 89(4):511-21
7) Hirano T  (1999) SMC-mediated chromosome mechanics: a conserved scheme from bacteria to vertebrates? Genes Dev 13(1):11-9
8) 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