The domain within your query sequence starts at position 5 and ends at position 158; the E-value for the P21-Arc domain shown below is 2.5e-71.

LATFKLSPPGRNRTREAKDTDIVDEAIYYFKANVFFKNYEIKNEADRTLIYITLYISECL
KKLQKCNSKSQGEKEMYTLGITNFPIPGEPGFPLNAIYAKPASKQEDEMMRAYLQQLRQE
TGLRLCEKVFDPQSDKPSKWWTCFVKRQFMNKSL

P21-Arc

P21-Arc
PFAM accession number:PF04062
Interpro abstract (IPR007204):

Arp2/3 binds to pre-existing actin filaments and nucleates new daughter filaments, and thus becomes incorporated into the dynamic actin network at the leading edge of motile cells and other actin-based protrusive structures [ (PUBMED:9600938) ]. In order to nucleate filaments, Arp2/3 must bind to a member of the N-WASp/SCAR family protein [ (PUBMED:9889097) ]. Arp2 and Arp3 are thought to be brought together after activation, forming an actin-like nucleus for actin monomers to bind and create a new actin filament. In the absence of an activating protein, Arp2/3 shows very little nucleation activity. Recent research has focused on the binding and hydrolysis of ATP by Arp2 and Arp3 [ (PUBMED:11752435) ], and crystal structures of the Arp2/3 complex have been solved [ (PUBMED:15505213) ].

The human complex consists of Arp2/3 complex composed of ARP2, ARP3, ARPC1B/p41-ARC, ARPC2/p34-ARC, ARPC3/p21-ARC, ARPC4/p20-ARC and ARPC5/p16-ARC. This family represents the ARPC3/p21-ARC subunit.

GO process:regulation of actin filament polymerization (GO:0030833), Arp2/3 complex-mediated actin nucleation (GO:0034314)
GO component:Arp2/3 protein complex (GO:0005885), cytoskeleton (GO:0005856)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry P21-Arc