This protein has 2 domains that are similar. Each domain is composed of 8 beta-strands. The first 4 strands in each domain appear to be duplicated, to make the last 4 strands. In other words, a double duplication during evolution. The N-terminus is in green. Each color makes a Greek key motif. Each sheet contains 3 strands of one color, and one of a different color.

Lindley, P., Najmudin, S., Bateman, O., Slingsby, C., Myles, D., Kumaraswamy, V. S., Glover, I.: STRUCTURE OF BOVINE GAMMA-B-CRYSTALLIN AT 150-K. JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS 89 pp. 2677 (1993)
(PubMed)

1gcs (PDB)