An LL-diaminopimelate aminotransferase defines a novel variant of the lysine biosynthesis pathway in plants

André O. Hudson, Bijay K. Singh, Thomas Leustek, Charles Gilvarg

Research output: Contribution to journalArticlepeer-review

88 Scopus citations

Abstract

Although lysine (Lys) biosynthesis in plants is known to occur by way of a pathway that utilizes diaminopimelic acid (DAP) as a central intermediate, the available evidence suggests that none of the known DAP-pathway variants found in nature occur in plants. A new Lys biosynthesis pathway has been identified in Arabidopsis (Arabidopsis thaliana) that utilizes a novel transaminase that specifically catalyzes the interconversion of tetrahydrodipicolinate and LL-diaminopimelate, a reaction requiring three enzymes in the DAP-pathway variant found in Escherichia coli. The LL-DAP aminotransferase encoded by locus At4g33680 was able to complement the dapD and dapE mutants of E. coli. This result, in conjunction with the kinetic properties and substrate specificity of the enzyme, indicated that LL-DAP aminotransferase functions in the Lys biosynthetic direction under in vivo conditions. Orthologs of At4g33680 were identified in all the cyanobacterial species whose genomes have been sequenced. The Synechocystis sp. ortholog encoded by locus sll0480 showed the same functional properties as At4g33680. These results demonstrate that the Lys biosynthesis pathway in plants and cyanobacteria is distinct from the pathways that have so far been defined in microorganisms.

Original languageEnglish (US)
Pages (from-to)292-301
Number of pages10
JournalPlant physiology
Volume140
Issue number1
DOIs
StatePublished - Jan 2006

All Science Journal Classification (ASJC) codes

  • Physiology
  • Genetics
  • Plant Science

Fingerprint Dive into the research topics of 'An LL-diaminopimelate aminotransferase defines a novel variant of the lysine biosynthesis pathway in plants'. Together they form a unique fingerprint.

Cite this