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- * DEAD and DEAH box families ATP-dependent helicases signatures *
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-
- A number of eukaryotic and prokaryotic proteins have been characterized [1,2,
- 3] on the basis of their structural similarity. They all seem to be involved
- in ATP-dependent, nucleic-acid unwinding. Proteins currently known to belong
- to this family are:
-
- - Initiation factor eIF-4A. Found in mammals, this protein is a subunit of a
- high molecular weight complex involved in 5'cap recognition and the binding
- of mRNA to ribosomes. It is an ATP-dependent RNA-helicase.
- - TIF1/TIF2, two yeast genes coding for the yeast analogues of eIF-4A.
- - PRP5 and PRP28. These yeast proteins are involved in various ATP-requiring
- steps of the pre-mRNA splicing process.
- - Pl10, a mouse protein expressed specifically during spermatogenesis.
- - An3, a Xenopus putative RNA helicase, closely related to Pl10.
- - Spp81/DED1 and DBP1, two yeast proteins probably involved in pre-mRNA
- splicing and related to Pl10.
- - Caenorhabditis elegans helicase glh-1.
- - Caenorhabditis elegans hypothetical proteins T26G10.1, ZK512.2 and ZK686.2.
- - MSS116, a yeast protein required for mitochondrial splicing.
- - SPB4, a yeast protein involved in the maturation of 25S ribosomal RNA.
- - p68, a human nuclear antigen. p68 has ATPase and DNA-helicase activities in
- vitro. It is involved in cell growth and division.
- - Rm62, a Drosophila putative RNA helicase related to p68.
- - DBP2, a yeast protein related to p68.
- - DRS1, a yeast protein involved in ribosome assembly.
- - Vasa, a Drosophila protein important for oocyte formation and specification
- of of embryonic posterior structures.
- - Me31B, a Drosophila maternally expressed protein of unknown function.
- - dbpA, an Escherichia coli putative RNA helicase.
- - deaD, an Escherichia coli putative RNA helicase which can suppress a
- mutation in the rpsB gene for ribosomal protein S2.
- - rhlB, an Escherichia coli putative RNA helicase.
- - srmB, an Escherichia coli protein that shows RNA-dependent ATPase activity.
- It probably interacts with 23S ribosomal RNA.
-
- All these proteins share a number of conserved sequence motifs. Some of them
- are specific to this family while others are shared by other ATP-binding
- proteins or by proteins belonging to the helicases `superfamily' [4]. One of
- these motifs, called the 'D-E-A-D-box', represents a special version of the B
- motif of ATP-binding proteins.
-
- Some other proteins belong to a subfamily which have His instead of the second
- Asp and are thus said to be `D-E-A-H-box' proteins [3,5,6]. Proteins currently
- known to belong to this subfamily are:
-
- - PRP2, PRP16 and PRP22. These yeast proteins are all involved in various
- ATP-requiring steps of the pre-mRNA splicing process.
- - Fission yeast prh1, which my be involved in pre-mRNA splicing.
- - Male-less (mle), a Drosophila protein required in males, for dosage
- compensation of X chromosome linked genes.
- - RAD3 from yeast. RAD3 is a DNA helicase involved in excision repair of DNA
- damaged by UV light, bulky adducts or cross-linking agents. Fission
- yeast RAD15 (rhp3) and mammalian DNA excision repair protein XPD (ERCC-2)
- are the homologs of RAD3.
- - Yeast CHL1 (or CTF1), which is important for chromosome transmission and
- normal cell cycle progression in G(2)/M.
- - Yeast TPS1.
- - Yeast hypothetical proteins YKL078w.
- - Caenorhabditis elegans hypothetical proteins C06E1.10 and K03H1.2.
- - Poxviruses' early transcription factor 70 Kd subunit which acts with RNA
- polymerase to initiate transcription from early gene promoters.
- - I8, a putative vaccinia virus helicase.
-
- We have developed signature patterns for both subfamilies.
-
- -Consensus pattern: [LIVM](2)-D-E-A-D-[RKEN]-x-[LIVMFYGSTN]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: Scherffelia dubia caltractin.
-
- -Consensus pattern: [GSAH]-x-[LIVMF](3)-D-E-[ALIV]-H-[NECR]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: Sulfolobus solfataricus trpG and
- Bacillus subtilis levR.
-
- -Note: proteins belonging to this family also contain a copy of the ATP-
- binding motif A (see the relevant section).
-
- -Expert(s) to contact by email: Linder P.
- linder@urz.unibas.ch
-
- -Last update: June 1994 / Patterns and text revised.
-
- [ 1] Schmid S.R., Linder P.
- Mol. Microbiol. 6:283-292(1992).
- [ 2] Linder P., Lasko P., Ashburner M., Leroy P., Nielsen P.J., Nishi K.,
- Schnier J., Slonimski P.P.
- Nature 337:121-122(1989).
- [ 3] Wassarman D.A., Steitz J.A.
- Nature 349:463-464(1991).
- [ 4] Hodgman T.C.
- Nature 333:22-23(1988) and Nature 333:578-578(1988) (Errata).
- [ 5] Harosh I., Deschavanne P.
- Nucleic Acids Res. 19:6331-6331(1991).
- [ 6] Koonin E.V., Senkevich T.G.
- J. Gen. Virol. 73:989-993(1992).
-