BTT1/YDR252W Summary Help

Standard Name BTT1 1
Systematic Name YDR252W
Feature Type ORF, Verified
Description Heterotrimeric nascent polypeptide-associated complex beta3 subunit; complex binds ribosomes via its beta-subunits in close proximity to nascent polypeptides; interacts with Caf130p of the CCR4-NOT complex; similar to human BTF3; BTT1 has a paralog, EGD1, that arose from the whole genome duplication (1, 2, 3, 4 and see Summary Paragraph)
Name Description BTf Three 1
Chromosomal Location
ChrIV:963412 to 963861 | ORF Map | GBrowse
Gene Ontology Annotations All BTT1 GO evidence and references
  View Computational GO annotations for BTT1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Classical genetics
Large-scale survey
39 total interaction(s) for 29 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 4
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 9
  • Co-fractionation: 4
  • Two-hybrid: 10

Genetic Interactions
  • Negative Genetic: 3
  • Phenotypic Enhancement: 3
  • Synthetic Growth Defect: 3

Expression Summary
Length (a.a.) 149
Molecular Weight (Da) 16,620
Isoelectric Point (pI) 9.2
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIV:963412 to 963861 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..450 963412..963861 2011-02-03 1996-07-31
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 SGDIDS000002660

BTT1 encodes the beta3 subunit of the nascent polypeptide-associated complex (NAC) (alpha, beta1, beta3). The alpha and beta1 subunits are encoded by EGD2 and EGD1, respectively. This complex binds to ribosomes via the beta-subunits in a salt-sensitive manner, in close proximity to nascent polypeptides (2). Loss of BTT1 has little effect, but cells lacking both Btt1p and Egd1p, which are similar in sequence and are both homologs of human BTF3L3, display several phenotypes (1). These include inability to grow at 37C (2), increased expression of GAL1 and GAL10, and also elevated expression of ACT1 and SSO1 (1). The lack of a drastic phenotype at optimal conditions of cells missing subunits of the NAC, coupled with inferred variability in complex composition, suggests either the existence of a substitute for the NAC or that cells tolerate the absence of the NAC (2).

Last updated: 2004-11-05 Contact SGD

References cited on this page View Complete Literature Guide for BTT1
1) Hu GZ and Ronne H  (1994) Yeast BTF3 protein is encoded by duplicated genes and inhibits the expression of some genes in vivo. Nucleic Acids Res 22(14):2740-3
2) Reimann B, et al.  (1999) Initial characterization of the nascent polypeptide-associated complex in yeast. Yeast 15(5):397-407
3) Byrne KP and Wolfe KH  (2005) The Yeast Gene Order Browser: combining curated homology and syntenic context reveals gene fate in polyploid species. Genome Res 15(10):1456-61
4) Cui Y, et al.  (2008) Genome wide expression analysis of the CCR4-NOT complex indicates that it consists of three modules with the NOT module controlling SAGA-responsive genes. Mol Genet Genomics 279(4):323-37