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We are deeply saddened by the passing of Amos Bairoch (1957–2025), the creator of PROSITE. We wish to dedicate our latest paper, published shortly before his death, to him. He will always be a source of inspiration to us.
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Amos Bairoch

PROSITE documentation PDOC51644
OST-type HTH domain profile


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PURL: https://purl.expasy.org/prosite/documentation/PDOC51644

Description

The OST-HTH (Oskar-TDRD5/TDRD7 HTH) [1] or LOTUS (after Limkain-b1, Oskar and TUdor-containing proteins 5 and 7) [2] domain is a motif of about 80 amino acids and is likely to adopt a winged helix-turn-helix (wHTH) fold, which is characterized by a core 3-stranded HTH with a C-terminal extension of two strands. The OST-HTH domain is primarily found in eukaryotes and bacteria with very rare occurences in archaea that appear to be relatively late lateral transfers of bacterial versions.

The OST-HTH domain is likely to bind RNA with a potential specificity for double-standed RNA (dsRNA) and might have key role in the assembly and localization of RNA-protein complexes with important post-transcriptional regulatory functions.

Some proteins known to contain a OST-HTH domain are listed below:

  • Animal Limkain-b1 (LKAP).
  • Vertebrate Tudor domain-containing protein 5 (TDRD5), required during spermiogenesis to participate in the repression transposable elements and prevent their mobilization, which is essential for the germline integrity.
  • Vertebrate Tudor domain-containing protein 7 (TDRD7), probably acts by binding to specific mRNAs and regulating their translation.
  • Drosophila maternal effect protein oskar (osk), organizes the germ plasm and directs localization of the posterior determinant nanos.

The profile we developed covers the entire OST-HTH domain.

Last update:

May 2012 / First entry.

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Technical section

PROSITE method (with tools and information) covered by this documentation:

HTH_OST, PS51644; OST-type HTH domain profile  (MATRIX)


References

1AuthorsAnantharaman V. Zhang D. Aravind L.
TitleOST-HTH: a novel predicted RNA-binding domain.
SourceBiol. Direct 5:13-13(2010).
PubMed ID20302647
DOI10.1186/1745-6150-5-13

2AuthorsCallebaut I. Mornon J.P.
TitleLOTUS, a new domain associated with small RNA pathways in the germline.
SourceBioinformatics 26:1140-1144(2010).
PubMed ID20305267
DOI10.1093/bioinformatics/btq122



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