BioGenes GmbH, Koepenicker Strasse 325, Berlin, Germany.
Arch Microbiol. 2010 Jan;192(1):1-14. doi: 10.1007/s00203-009-0523-6. Epub 2009 Nov 10.
Gene PA1990 of Pseudomonas aeruginosa, located downstream of pqqE and encoding a putative peptidase, was shown to be involved in excretion of PQQ into the culture supernatant. This gene is cotranscribed with the pqqABCDE cluster and was named pqqH. A PA1990::Km(r) mutant (VK3) did not show any effect in growth behaviour; however, in contrast to the wild-type, no excretion of PQQ into the culture supernatant was observed. The putative pqqF gene of P. aeruginosa was shown to be essential for PQQ biosynthesis. A pqqF::Km(r) mutant did not grow aerobically on ethanol, because of its inability to produce PQQ. Transcription of the pqqABCDEH operon was induced upon aerobic growth on ethanol, 1-propanol, 1,2-propanediol and 1-butanol, while on glycerol, succinate and acetate, transcription was low. Transcription of the pqqABCDEH operon was also found upon anoxic growth on ethanol with nitrate as electron acceptor, but no PQQ was produced. Expression of the pqqABCDEH operon is regulated at the transcriptional level. In contrast, the pqqF operon appeared to be transcribed constitutively at a very low level under all growth conditions studied.
铜绿假单胞菌基因 PA1990 位于 pqqE 下游，编码一种假定的肽酶，被证明参与 PQQ 向培养上清液的排泄。该基因与 pqqABCDE 簇共转录，并被命名为 pqqH。PA1990::Km(r)突变体 (VK3) 在生长行为上没有任何影响；然而，与野生型相比，没有观察到 PQQ 排泄到培养上清液中。铜绿假单胞菌的假定 pqqF 基因被证明对 PQQ 生物合成是必需的。pqqF::Km(r)突变体不能在有氧条件下以乙醇为碳源生长，因为它不能产生 PQQ。在有氧条件下以乙醇、1-丙醇、1,2-丙二醇和 1-丁醇生长时，pqqABCDEH 操纵子的转录被诱导，而在甘油、琥珀酸盐和醋酸盐上，转录水平较低。在以硝酸盐作为电子受体的有氧条件下以乙醇作为碳源进行缺氧生长时，也发现了 pqqABCDEH 操纵子的转录，但没有产生 PQQ。pqqABCDEH 操纵子的转录是在转录水平上受到调节的。相比之下，pqqF 操纵子似乎在所有研究的生长条件下以非常低的水平组成性转录。
