Family of bacterial and phage baseplate assembly proteins responsible for forming the small spike at the end of the tail or bacterial pathogenic needle-shaft [1]. This entry represents the OB fold part of the structure. This structure contains an unusual extra beta hairpin that forms the foundation of the spike protein's beta helix [3].

1: Bacteriophage P2: genes involved in baseplate assembly. Haggard-Ljungquist E, Jacobsen E, Rishovd S, Six EW, Nilssen O, Sunshine MG, Lindqvist BH, Kim KJ, Barreiro V, Koonin EV, et al.; Virology 1995;213:109-121. PMID:7483254

2: The rise of the Type VI secretion system. Filloux A; F1000Prime Rep. 2013;5:52. PMID:24381728

3: Phage pierces the host cell membrane with the iron-loaded spike. Browning C, Shneider MM, Bowman VD, Schwarzer D, Leiman PG; Structure. 2012;20:326-339. PMID:22325780