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. 1996 Jan;5(1):178–180. doi: 10.1002/pro.5560050124

Two domains of superfamily I helicases may exist as separate proteins.

E V Koonin 1, K E Rudd 1
PMCID: PMC2143243  PMID: 8771213

Abstract

DNA and RNA helicases of superfamily I are characterized by seven conserved motifs. The five N-terminal motifs are separated from the two C-terminal ones by a spacer that is highly variable in both sequence and length, suggesting the existence of two distinct domains. Using computer methods for protein sequence analysis, we show that PhoH, an ATP-binding protein that is conserved in Escherichia coli and Mycobacterium leprae, is homologous to the putative N-terminal domain of the helicases, whereas the putative E. coli protein YjhR is homologous to the C-terminal domain. These findings suggest that the N-and C-terminal domains of superfamily I helicases have distinct activities, with only the N-terminal domain having the ATPase activity. It is speculated that PhoH and YjhR have evolved from helicases through deletion of the portions of the helicase genes coding for the C- and N-terminal domain, respectively.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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