The domain within your query sequence starts at position 235 and ends at position 391; the E-value for the 3a1b domain shown below is 1e-101.

RKSTTEKPKVKEIIDERTRERLVYEVRQKCRNIEDICISCGSLNVTLEHPLFIGGMCQNC
KNCFLECAYQYDDDGYQSYCTICCGGREVLMCGNNNCCRCFCVECVDLLVGPGAAQAAIK
EDPWNCYMCGHKGTYGLLRRREDWPSRLQMFFANNHD

This is a PDB domain - please see the PDBSUM entry of 3a1b for further annotation