The UspA1 head domain is globally similar to other structures of TAA head domains and comprises a trimeric left-handed parallel beta-roll, which is formed from 14 repeating 14-16 residue segments that form a ladder of beta-strand coils [1]. This Pfam entry represents a single repeat unit of the beta-ladder.

1: Correlation of in situ mechanosensitive responses of the Moraxella catarrhalis adhesin UspA1 with fibronectin and receptor CEACAM1 binding. Agnew C, Borodina E, Zaccai NR, Conners R, Burton NM, Vicary JA, Cole DK, Antognozzi M, Virji M, Brady RL; Proc Natl Acad Sci U S A. 2011;108:15174-15178. PMID:21876142