4.2.99.B1 native and recombinant protein 4.2.99.B1 purified from recombinant protein of an Escherichia coli expression system 4.2.99.B1 recombinant C-terminal 98-kDA-fragment and the mutant enzyme D829N/E830Q are purified to near homogeneity 4.2.99.B1 recombinant C-terminally His6-tagged wild-type and mutant enzymes from Escherichia coli by immobilized-metal affinity chromatography and ultrafiltration 4.2.99.B1 recombinant His-tagged full-length enzyme Rev1 from in Escherichia coli, tag removal 4.2.99.B1 recombinant pol lambda and the K310A mutant are overexpressed in Eschercihia coli and purified to near homogeneity 4.2.99.B1 recombinant protein 4.2.99.B1 recombinant protein, copurification with DNA polymerase, proved by analytical gel filtration 4.2.99.B1 recombinant protein, expressed in Escherichia coli M15 (pREP4). The protein aggregates as inclusion bodies, solubilized in 5 M guanidinium hydrochloride and 20 mM imidazole-HCl, pH 8.0 and purified 4.2.99.B1 recombinant wild-type and mutant proteins H34G, K35A, K35R, Y39F, K68A, K68R, K72A, K72R, K35A/K68A, K35A/K72A, K35A/K68A/K72A, K35R/K68R/K72R are expressed in Escherichia coli and purified