Text S1 - Wolbachia Transcription Elongation Factor “Wol GreA” Interacts with α2ββ′σ Subunits of RNA Polymerase through Its Dimeric C-Terminal Domain

The 3D structural model of Wol GreA was developed through homology modeling approach using modeler9v10 tool and validated by different online tools for its reliability. The results obtained through Procheck, ERRAT, ProSA and ProQ web servers indicated that the developed model is consistent and having better validation outcomes with their template 1GRJ.Further protein-protein docking study was performed to identify the key residues of CTD responsible for dimerization. The docking study showed that Asp120, Val121, Ser122, Lys123, and Ser134 are the residues of Wol GreA CTD through which monomers of Wol GreA interact shaping into dimeric conformation. To explore the residual interaction mechanism between Wol GreA and α2ββ'σ subunits of Wol RNAP, the protein-protein docking studies using HEX program were implemented. The docking study between α- subunit and Wol GreA revealed that Wol CTD donor atoms HZ1& HZ3 of Lys140 involved in hydrogen (H) bonding with acceptor atom OG1 of Thr164 of Wol α subunit and Wol CTD acceptor atoms O, OD1& OD2 of Asp102 and O of Lys82 form H bonding with Wol α subunit donor atoms HD21& HD22 of Asn50; HH11, HH21& HH22 of Arg53, and HG1 of Thr88. The protein docking between β- subunit of RNAP and Wol GreA exhibited that CTD donor atoms H & HG of Ser105, HG of Ser127, and Ser129 formed H bonding with Wol RNAP β subunit acceptor atoms O, OD1& OD2 of Asp 1330; OD1 of Asp1331; O & OD1 of Asn528 and O of Ser529 and Wol CTD acceptor atoms OG of Ser98; OE2 of Glu116; O & OG of Ser129 and O of Val147 created H bonding by interacting with Wol RNAP β subunit donor atoms HZ1, HZ2& HZ3 of Lys163; H of Asn528, Ser529 & Ser530; HD22 of Asn589 and HH22 of Arg1359. Similar to α and β-subunits of RNAP, β′ also solely forms H bonding with CTD residues of Wol GreA where donor atom HG of Ser151 formed H bonding with acceptor atom O of Leu1178 of Wol RNAP β′ subunit and Wol CTD acceptor atoms O of Asp104; OH of Tyr109; O of Val121 & Ser122; OE2 of Glu153 and O of Phe163 involved in H bonding with donor atoms of Wol RNAP β′ subunit HH21 of Arg129; HH11 & HH21 of Arg1135; HZ1 of Lys1195; HH12 of Arg1211; H of Gly1297 and HH22 of Arg1300. The protein docking between σ-subunit of RNAP and Wol GreA exhibited that CTD acceptor atoms OE2 of Glu106 and OE1 of Glu143 created H bonding by interacting with donor atoms HZ1& HZ3 of Lys430 and HH12 of Arg478 of RNAP σ subunit. (DOC)