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Characterization And Assembly Of The Pseudomonas Aeruginosa Aspartate Transcarbamoylase-Pseudo Dihydroorotase Complex, Chandni Patel, Asmita Vaishnav, Brian Fp Edwards, David R. Evans

Biochemistry and Molecular Biology Faculty Publications

Pseudomonas aeruginosa is a virulent pathogen that has become more threatening with the emergence of multidrug resistance. The aspartate transcarbamoylase (ATCase) of this organism is a dodecamer comprised of six 37 kDa catalytic chains and six 45 kDa chains homologous to dihydroorotase (pDHO). The pDHO chain is inactive but is necessary for ATCase activity. A stoichiometric mixture of the subunits associates into a dodecamer with full ATCase activity. Unlike other known ATCases, the P. aeruginosa catalytic chain does not spontaneously assemble into a trimer. Chemical-crosslinking and size-exclusion chro- matography showed that P. aeruginosa ATCase is monomeric which accounts for its …