This family of proteins has no known function however the structure has been determined. The protein consists of two alpha-helices packed on the same side of a central beta-hairpin [1].

1: Solution structure of the hypothetical protein Mth677 from Methanobacterium thermoautotrophicum: a novel alpha+beta fold. Blanco FJ, Yee A, Campos-Olivas R, Ortiz AR, Devos D, Valencia A, Arrowsmith CH, Rico M; Protein Sci. 2004;13:1458-1465. PMID:15152082