Mutual Complementation ...._._.... .........__........._ ............13 Discussion .........._...._ ......... ...............139..... 4 DEVELOPMENT OF CYSTEINE CHEMICAL MODIFICATIONS OF ALTERED b SUB UNIT S ................. ................. 143........ ..... Introducti on ................. ...............143................ Materials and Methods .............. ...............146.... M materials ................ ...............146................ Strains and M edia ................. ...............146................ Recombinant DNA Techniques............... ..............14 Mutagenesis and Strain Construction ................. ............. ......... .......148 Crude Preparative Procedures .............. ...............152.... Assays of F1Fo ATP Synthase Activity .............. ...............152.... Immunoblot Analysis .............. ...............153.... Re sults................. .. .... ......... ..... ........ .. ..................5 Construction and Growth Characteristics of Mutants ................. ................. .153 Effects of Cysteine Mutations .............. .....................157 Discussion ................. ...............158................ 5 MUTAGENISIS OF THE AMINO AND CARBOXYL TERMINI OF THE b SUBUNIT INT F1Fo ATP SYNTHASE .............. ...............161.... Introducti on ................. ...............161................ M materials and M ethods .............. ...............165.... M materials ................ ...............165................ Strains and M edia ................. ...............165................ Recombinant DNA Techniques............... ..............16 Mutagenesis and Strain Construction ................. ............. ......... .......16 Crude Preparative Procedures .............. ...............168.... Assays of F1Fo ATP Synthase Activity .............. ...............169.... R e sults............... .. .............. ...............169...... Amino Terminal Mutations ............... .. .. .... ..... .. ............... 169.... Construction and growth characteristics of mutants .............. ................. 169 Effects of amino terminal mutations .............. .....................171 Carboxyl Terminal Mutations ............... ........ ..............17 Construction and growth characteristics of mutants .............. ................. 173 Effects of carboxyl terminal mutation............... ................175 Discussion ................. ...............176................ 6 CONCLUSIONS AND FUTURE DIRECTIONS .............. .....................8 C onclusions............... .. .. ..... .. .. ... ...... .................18 Integration of Unequal Length b Subunits into F1Fo ATP Synthase ................. 181