Fig. 1.

Comparing various forms of ribosome hibernation factors. (a) Schematic representation of domain organization in short and long variants of Hpf (named Hpf^short and Hpf^long, respectively), YfiA and PSRP1. It should be noted that despite an extended C-terminal region in PSRP1 (also referred to as protein Y), it forms a hibernating 70S ribosome. This is also observed for the ribosome hibernation factor in mycobacteria (MSMEG_1878), which is therefore named mycobacterial protein Y (Mpy). (b) Alignment of the protein sequences of representative ribosome hibernation factors from each of the categories shown in (a). An additional N-terminal extension of variable length in PSRP1 and Mpy is notable.