Understanding the behavioural difference of PPCA among its homologs in   C7 family towards recognition of DXCA
  Among all the proteins of Periplasmic C type cytochrome A (PPCA) family obtained from cytochrome C7 found in Geobacter sulfurreducens, PPCA protein can interact with Deoxycholate (DXCA), while its other homologs do not, as observed from the crystal structures. Utilizing the concept of 'structure-function relationship', an effort has been initiated towards understanding the driving force for recognition of DXCA exclusively by PPCA among its homologs. Further, a combinatorial analysis of the binding sequences (contiguous sequence of amino acid residues of binding locations) is performed to build graph-theoretic models, which show that PPCA differs from its homologues. Analysis of the results suggests that the underlying impetus of recognition of DXCA by PPCA is embedded in its primary sequence and 3D conformation. 
Suvankar Ghosh, Shankar Kumar Ghosh, Camellia Ray, Goutam Paul,   Pabitra Pal Choudhury, Raja Banerjee
q-bio.BM