Su-var(3)9, SuVar3-9, SUV39, ptn
Gene model reviewed during 5.42
Genes with CDS overlap: eIF-2gamma and Su(var)3-9 share promoter, first exon and N-terminal coding sequences (80 residues); overlapping structure not conserved outside of insects (see FBrf0189765).
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.55
There is only one protein coding transcript and one polypeptide associated with this gene
635, 475 (aa); 51 (kD predicted)
Interacts with Su(var)205 and Su(var)3-7. Probably associates with Rpd3.
Although the SET domain contains the active site of enzymatic activity, both pre-SET and post-SET domains are required for methyltransferase activity. The SET domain also participates in stable binding to heterochromatin (By similarity).
In the pre-SET domain, Cys residues bind 3 zinc ions that are arranged in a triangular cluster; some of these Cys residues contribute to the binding of two zinc ions within the cluster.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Su(var)3-9 using the Feature Mapper tool.
GBrowse - Visual display of RNA-Seq signalsView Dmel\Su(var)3-9 in GBrowse 2
Genetic map position of Su(var)3-9306 mutation on Gl Sb H chromosome is at 57.9 and on the cv-c Sb chromosome locus is at 56.4. Genetic map position of Su(var)3-9310 mutation on Gl Sb H chromosome is at 56.7 and on the cv-c Sb chromosome locus is at 56.5. Genetic map position of Su(var)3-9328 mutation on Gl Sb H chromosome is at 57.3 and on the cv-c Sb chromosome locus is at 56.4. Genetic map position of Su(var)3-9340 mutation on Gl Sb H chromosome is at 55.6 and on the cv-c Sb chromosome locus is at 56.9. Genetic map position of Su(var)3-9322 mutation on Gl Sb H chromosome is at 57.8 and on the cv-c Sb chromosome locus is at 56.4. Genetic map position of Su(var)3-9336 mutation on Gl Sb H chromosome is at 54.9 and on the cv-c Sb chromosome locus is at 56.2.
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
FlyBase curator comment: Su(var)3-9ptn was reported to be allelic to two P-element insertion alleles at 67C (l(3)S089004S089004 and l(3)S089004S089302) in FBrf0134644. However, FBrf0180260 demonstrates that Su(var)3-9ptn is an allele of Su(var)3-9 (at 88E) and that the l(3)S089004S089004 and l(3)S089004S089302 alleles at 67C represent a separate "modifier of dominant female sterility" locus.
The genomic region around Su(var)3-9 encodes two classes of transcript (2.4kb and 2.0kb), which show a 330bp overlap at their 5' ends, producing an overlap of 80 amino acids at the N-terminal ends of the encoded proteins. The encoded proteins are otherwise different in sequence. The 2.4kb transcript encodes Su(var)3-9 and the 2.0kb transcript encodes eIF-2γ.
DNA-protein interactions: genome-wide binding profile assayed for Su(var)3-9 protein in Kc167 cells; see Chromatin_types_NKI collection report. Individual protein-binding experiments listed under "Samples" at GEO_GSE22069 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE22069).
The organisation of nucleosomes over the entire histone complex region is altered in Su(var)3-9 mutants and there is a concomitant increase in expression of the histone genes.
Su(var)3-9 is a haplo suppressor and a triplo enhancer and a non-essential gene. The suppressor effect of mutations dominate over enhancer mutations of over 40 different haplo-dependent enhancer genes. Results indicate that Su(var)3-9 plays an important role in the regulation of gene inactivation through heterochromatinization in position effect variegation (PEV). Su(var)3-9 mutations are epistatic to E(var)2-88.
Su(var) mutants have dramatic effects on chromosome morphology and gene expression but negligible effects on nuclease sensitivity of the w gene chromatin: changes due to alterations in chromosomal packaging.
The gene is named after "Pitkin", the principal figure in Robert Ascher's movie "A Stitch in Time", who caused perplexing confusions by overdoing almost everything.