Many of the O cluster phage have a derivative of MPME1, its clearly not a MPME2 but is rather a truncation. See this alignment as an example:

Alignment to BPs_58 to JangDynasty gp22 (but several O phage have identical sequence):
Query  1    MFPITDTRREMTTMPTTEHGSDVQHLSPEHRDRAWRDRFNARWHYDYGGWIRTRPQDEAS  60
            MFPITDTRREMTTMPTTEHGSDVQHLSPEHRDRAWRDRFNARWHYDYGGWIRTRPQDEAS
Sbjct  1    MFPITDTRREMTTMPTTEHGSDVQHLSPEHRDRAWRDRFNARWHYDYGGWIRTRPQDEAS  60

Query  61   TFALIPTKHYGPFTEDHSCPACLVVHPPEDCPVLSGNTDML———————VVFD-YDTSPNK  112
            TFALIPTKHYGPFTEDHSCPACLVVHPPEDCPVLSGNTD+         +FD +D+ P
Sbjct  61   TFALIPTKHYGPFTEDHSCPACLVVHPPEDCPVLSGNTDIFGTTSSGPTIFDSFDSGPGG  120

Query  113  A  113

Sbjct  121  V  121

As per Cresawn et al PLoS ONE 10(3) these should be annotated MPME1 even though they are truncations.