PFRMAT TS 
TARGET T0065 
AUTHOR 7397-8542-2481 
METHOD PSI-Blast searches showed that SinR is related to phage repressors and 
METHOD that SinI is homologous to the C-terminal 40 residues of SinR. These 
METHOD findings were confirmed by the abstract posted on the CASP web site. A 
METHOD 3D superposition of phage repressors was made in order to identify 
METHOD conserved features and SinR was aligned by maximum overlap of the 
METHOD hydrophobic positions. The C-terminal 40 residues of SinR and the entire 
METHOD SinI protein failed to yield significant matches to proteins in the pdb 
METHOD database. Secondary structure prediction using the JPred server 
METHOD indicated the existence of two helices in each protein. The first is 
METHOD proposed to dimerize between SinR and SinI in the same fashion and in a 
METHOD similar position as the C-terminal helix in lambda C1 repressor 
METHOD (antiparallel, left-handed, 25 deg crossing angle) and the second is 
METHOD proposed to dimerize in a parallel, right-handed way at approximately 30 
METHOD deg crossing angle (the N-terminal helix of CreI endonuclease is 
METHOD included as the template). The first helix is oriented parallel to the 
METHOD DNA and the second helix perpendicular. 
MODEL  1 
PARENT NONE 
TER 
END 
