Protein Family Models

This is the C-terminal MrfA Zn+2-binding domain (MZB, also referred to as DUF1998) which contains a conserved four-cysteine signature motif. These four Cys reside in a short coil between two alpha-helices and form a metal ion-binding site [1]. This domain is frequently found at the C-terminal of ndNTPases, however, it is also found encoded in a standalone gene, downstream of putative helicase domain-encoding genes associated with bacterial anti-phage defense system DISARM. MrfA (Mitomycin repair factor A, also known as YprA in Bacillus subtilis) is a DNA helicase that supports repair of mitomycin C-induced DNA damage. MrfA homologues are widely distributed in bacteria and are also present in archaea, fungi and plants. The MrfA-homologue in yeast, Hrq1, also reduces mitomycin C sensitivity. Hrq1 has high similarity to human RecQ4 and was therefore assigned to the RecQ-like helicase family. MrfA homologues appear to be missing in Enterobacteria, however, certain pathogenic Escherichia coli and Salmonella strains harbour Z5898-like helicases with this domain [1]. [1]. 33300032. A skipping rope translocation mechanism in a widespread family of DNA repair helicases. Roske JJ, Liu S, Loll B, Neu U, Wahl MC;. Nucleic Acids Res. 2021;49:504-518. (from Pfam)

Date:

2024-10-16

Members of this family include the DEAD and DEAH box helicases. Helicases are involved in unwinding nucleic acids. The DEAD box helicases are involved in various aspects of RNA metabolism, including nuclear transcription, pre mRNA splicing, ribosome biogenesis, nucleocytoplasmic transport, translation, RNA decay and organellar gene expression. [1]. 10322435. Unwinding RNA in Saccharomyces cerevisiae: DEAD-box proteins and related families. de la Cruz J, Kressler D, Linder P;. Trends Biochem Sci 1999;24:192-198. [2]. 9862990. The DEAD box RNA helicase family in Arabidopsis thaliana. Aubourg S, Kreis M, Lecharny A;. Nucleic Acids Res 1999;27:628-636. (from Pfam)

Date:

2024-10-16

The Prosite family is restricted to DEAD/H helicases, whereas this domain family is found in a wide variety of helicases and helicase related proteins. It may be that this is not an autonomously folding unit, but an integral part of the helicase. (from Pfam)

Date:

2024-08-14