| putative evolutionary origin of plasmids carrying the genes involved in leucine biosynthesis in buchnera aphidicola (endosymbiont of aphids). | an 8.5-kb plasmid encoding genes (leuabcd) involved in leucine biosynthesis and a small plasmid of 1.74 kb of yet unknown function were found in the intracellular symbiont, buchnera aphidicola, of two divergent aphid species, thelaxes suberi and tetraneura caerulescens, respectively. the leuabcd-carrying plasmid (pbts1) was amplified from total aphid dna by inverse long pcr, using outwardly oriented oligonucleotide primers specific to leua. the resulting 8.2-kb pcr fragment as well as the 1.74-k ... | 1997 | 9244264 |
| plasmid-encoded anthranilate synthase (trpeg) in buchnera aphidicola from aphids of the family pemphigidae. | buchnera aphidicola is an obligate intracellular symbiont of aphids. one of its proposed functions is the synthesis of essential amino acids, nutrients required by aphids but deficient in their diet of plant phloem sap. the genetic organization of the tryptophan pathway in buchnera from proliferous aphids of the family aphididae has previously been shown to reflect a capacity to overproduce this essential amino acid (c.-y. lai, l. baumann, and p. baumann, proc. natl. acad. sci. usa 91:3819-3823, ... | 1999 | 9872768 |