PubMed:10103278 JSONTXT

{"project":"PMID_GLOBAL","denotations":[{"id":"T1","span":{"begin":0,"end":102},"obj":"Sentence"},{"id":"T2","span":{"begin":103,"end":163},"obj":"Sentence"},{"id":"T3","span":{"begin":164,"end":339},"obj":"Sentence"},{"id":"T4","span":{"begin":340,"end":453},"obj":"Sentence"},{"id":"T5","span":{"begin":454,"end":535},"obj":"Sentence"},{"id":"T6","span":{"begin":536,"end":614},"obj":"Sentence"},{"id":"T7","span":{"begin":615,"end":671},"obj":"Sentence"},{"id":"T8","span":{"begin":672,"end":789},"obj":"Sentence"},{"id":"T9","span":{"begin":790,"end":869},"obj":"Sentence"},{"id":"T10","span":{"begin":870,"end":1003},"obj":"Sentence"},{"id":"T11","span":{"begin":1004,"end":1065},"obj":"Sentence"},{"id":"T12","span":{"begin":1066,"end":1175},"obj":"Sentence"},{"id":"T13","span":{"begin":1176,"end":1344},"obj":"Sentence"}],"text":"cumA, a gene encoding a multicopper oxidase, is involved in Mn2+ oxidation in Pseudomonas putida GB-1.\nPseudomonas putida GB-1-002 catalyzes the oxidation of Mn2+. Nucleotide sequence analysis of the transposon insertion site of a nonoxidizing mutant revealed a gene (designated cumA) encoding a protein homologous to multicopper oxidases. Addition of Cu2+ increased the Mn2+-oxidizing activity of the P. putida wild type by a factor of approximately 5. The growth rates of the wild type and the mutant were not affected by added Cu2+. A second open reading frame (designated cumB) is located downstream from cumA. Both cumA and cumB probably are part of a single operon. The translation product of cumB was homologous (level of identity, 45%) to that of orf74 of Bradyrhizobium japonicum. A mutation in orf74 resulted in an extended lag phase and lower cell densities. Similar growth-related observations were made for the cumA mutant, suggesting that the cumA mutation may have a polar effect on cumB. This was confirmed by site-specific gene replacement in cumB. The cumB mutation did not affect the Mn2+-oxidizing ability of the organism but resulted in decreased growth. In summary, our data indicate that the multicopper oxidase CumA is involved in the oxidation of Mn2+ and that CumB is required for optimal growth of P. putida GB-1-002."}