DNA helicase B (hDHB, HELB)

Function

• unwinds duplex DNA with 5'-3' polarity
• single- strand DNA-dependent ATPase & DNA helicase activities
• prefers ATP & dATP as substrates
• binds to RPA1 & at least two subunits of pol-prim
• binds strongly to single-stranded DNA in the absence of ATP but dissociates readily in the presence of 1 mM ATP
• phosphorylated upon DNA damage, probably by ATM or ATR

Inhibition:

• inhibited by salt concentration > 100 mM

Cofactor: uses either Mg+2 or Mn+2 to support helicase activity.

Alternative splicing

named isoforms=2

Expression

• expressed in testis & thymus > liver, spleen, kidney & brain

More general terms

• helicase (DNA unwinding protein, DNA untwisting protein)
• phosphoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/Q8NG08.html