This short repeat consists of the motif WXXh where X can be any residue and h is a hydrophobic residue. The repeat is name TMP after its occurrence in the tape measure protein (TMP). Tape measure protein is a component of phage tail and probably forms a beta-helix. Truncated forms of TMP lead to shortened tail fibres [1]. This repeat is also found in non-phage proteins where it may play a structural role.

1: Mutational analysis of two structural genes of the temperate lactococcal bacteriophage TP901-1 involved in tail length determination and baseplate assembly. Pedersen M, Ostergaard S, Bresciani J, Vogensen FK; Virology 2000;276:315-328. PMID:11040123