Cloning of a sequence of Aquaspirillum magnetotacticum that complements the aroD gene of Escherichia coli

Abstract

A 2 kb DNA fragment isolated from a cosmid library of Aquaspirillum magnetotacticum strain MS-1 complements the aromatic-metabolite requirements and iron-uptake deficiencies of Escherichia coli and Salmonella typhimurium strains that lack a functional aroD (biosynthetic dehydrodquinase) sequence. All recombinant cosmids selected for their aroD complementation property carry this sequence. No DNA sequence homology has, however, been detected by Southern hybridization between the cloned fragment and the aroD gene of E. coli or the qa2 (catabolic dehydroquinase) gene of Neurospora crassa.

Magnetosome formation in prokaryotes

“…They cloned, sequenced and characterized the recA gene from M. magnetotacticum 105,106 . Focusing on iron uptake in M. magnetotacticum, they also cloned and characterized a 2-kb DNA fragment that comple mented the aroD (biosynthetic dehydroquinase) gene function in E. coli and Salmonella enterica serovar Typhimurium 107 . aroD mutants of these strains cannot take up iron from the growth medium.…”

Biologically Controlled Mineralization of Magnetic Iron Minerals by Magnetotactic Bacteria

“…medium. In In other other words, words, when when the the 2-kb 2-kb DNA DNA fragment fragment from from M. M. magnetofClcficlim magnetofClcficlim was was intro intro duced duced into into these these mutants, mutants, the the ability ability of of the the mutants mutants to to take take up up iron iron from from the the growth growth medium medium was was restored restored (22), (22), suggesting suggesting that that the the 2-kb 2-kb DNA DNA fragment fragment may may be be im im portant portant in in iron iron uptake uptake (and (and therefore therefore possibly possibly in in magnetite magnetite synthesis) synthesis) in in M. M. mag mag netofacticum. netofacticum.…”

“…netofacticum. Although Although the the cloned cloned fragment fragment restored restored iron iron uptake uptake deficiencies deficiencies in in siderophoreless, siderophoreless, iron iron uptake-deficient uptake-deficient mutants mutants of of E. E. coli, coli, it it did did not not mediate mediate sider sider ophore ophore biosynthesis biosynthesis (22). (22).…”

Genetic Engineering of Single-Domain Magnetic Bacteria.

“…The nitrocellulose Filters were baked in an 80 C vacuum Results ov en for 2 h and hybridized for 22 to 24 h at 45 C in a solution containing, 50%, formamnide. 5 functions. Library clones that trow in the presence of %IMS at -70 C using, an intensifving screen (Cronex Hi-Plus).…”