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0  structures 121  species 0  interactions 297  sequences 2  architectures

Family: SUN (PF03856)

Summary: Beta-glucosidase (SUN family)

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This is the Wikipedia entry entitled "SUN domain". More...

SUN domain Edit Wikipedia article

Symbol Sad1_UNC
Pfam PF07738
Pfam clan CL0202
InterPro IPR012919

SUN (Sad1p, UNC-84) domains are conserved C-terminal protein regions a few hundred amino acids long. SUN domains are usually found following a transmembrane domain and a less conserved region of amino acids. Most proteins containing SUN domains are thought to be involved in the positioning of the nucleus in the cell. It is thought that SUN domains interact directly with KASH domains in the space between the outer and inner nuclear membranes to bridge the nuclear envelope and transfer force from the nucleoskeleton to the cytoplasmic cytoskeleton. SUN proteins are thought to localize to the inner nuclear membrane.[1] The S. pombe Sad1 protein localises at the spindle pole body. In mammals, the SUN domain is present in two proteins, Sun1 and Sun2. The SUN domain of Sun2 has been demonstrated to be in the periplasm.[2][3]

Examples of SUN Proteins[edit]

Caenorhabditis elegans

  • SUN-1/matefin
  • UNC-84

Drosophila melanogaster

  • Klaroid
  • Spag4


  • SUN1, 2, and 3
  • SPAG4

Schizosaccharomyces pombe

  • Sad1p

Saccharomyces cerevisiae

  • Mps3p


  • SUN1, 2, 3, 4, and 5


  • SUN1, and 2


  1. ^ Tzur YB, Wilson KL, Gruenbaum Y (Oct 2006). "SUN-domain proteins: 'Velcro' that links the nucleoskeleton to the cytoskeleton". Nat Rev Mol Cell Biol. 7 (10): 782–8. doi:10.1038/nrm2003. PMID 16926857. 
  2. ^ Hodzic DM, Yeater DB, Bengtsson L, Otto H, Stahl PD (June 2004). "Sun2 is a novel mammalian inner nuclear membrane protein". J. Biol. Chem. 279 (24): 25805–12. doi:10.1074/jbc.M313157200. PMID 15082709. 
  3. ^ Raff JW (September 1999). "The missing (L) UNC?". Curr. Biol. 9 (18): R708–10. doi:10.1016/S0960-9822(99)80446-1. PMID 10508607. 

This article incorporates text from the public domain Pfam and InterPro IPR012919

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Beta-glucosidase (SUN family) Provide feedback

Members of this family include Nca3, Sun4 and Sim1. This is a family of yeast proteins, involved in a diverse set of functions (DNA replication, aging, mitochondrial biogenesis and cell septation)[1]. BGLA from Candida wickerhamii has been characterised as a Beta-glucosidase EC:

Literature references

  1. Mouassite M, Camougrand N, Schwob E, Demaison G, Laclau M, Guerin M; , Yeast 2000;16:905-919.: The 'SUN' family: yeast SUN4/SCW3 is involved in cell septation. PUBMED:10870102 EPMC:10870102

  2. Skory CD, Freer SN; , Appl Environ Microbiol 1995;61:518-525.: Cloning and characterization of a gene encoding a cell-bound, extracellular beta-glucosidase in the yeast Candida wickerhamii. PUBMED:7574590 EPMC:7574590

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR005556

This is a family of proteins is restricted to the fungi, the Saccharomycetales and Schizosaccharomycetales. In Saccharomyces cerevisiae (Baker's yeast)they have been termed the SUN gene family, whose products display high homology in their 258 amino acid C-terminal domain. SIM1, UTH1, NCA3 (SUN, the founding members and now including SUN4) are involved in different cellular processes: DNA replication, ageing, mitochondrial biogenesis and in the cell septation process (SUN4) [PUBMED:10870102].

NCA3 (Nuclear Control of ATPase), is one of the two nuclear genes involved in the control of mitochondrial expression of subunits 6 and 8 of the Fo-F1 ATP synthase in Saccharomyces cerevisiae (Baker s yeast). Mutations in either NCA2 (INTERPRO) or NCA3 dramatically lower the level of the co-transcript encoding subunits 6 and 8 [PUBMED:7723016, PUBMED:7586026]. Also, since NCA3 is one of the four S. cerevisiae genes of the SUN family other SUN family genes were tested; however only UTH1 (but not SUN4 or SIM1) was found to interfere with mitochondria biogenesis [PUBMED:10683261].

Domain organisation

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You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

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HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...


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Curation and family details

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Curation View help on the curation process

Seed source: DOMO:DM02469;
Previous IDs: none
Type: Family
Author: Finn RD
Number in seed: 50
Number in full: 297
Average length of the domain: 247.20 aa
Average identity of full alignment: 45 %
Average coverage of the sequence by the domain: 59.94 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 25.0 25.0
Trusted cut-off 82.4 81.7
Noise cut-off 17.0 22.3
Model length: 249
Family (HMM) version: 8
Download: download the raw HMM for this family

Species distribution

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