MDM2 GI:89993692 mouse double minute 2 homolog isoform MDM2b 1 mvrsrqmcnt nmsvptdgav ttsqipaseq etlvrpkpll lkllksvgaq 50 51 kdtytmkevl fylgqyimtk rlydekqqhi vycsndcanl fplvdlsire 100 101 lyisnyitlg i