Favorite Parts

RoxA - Rubber Oxygenase A

Part BBa_K1819003 corresponds to the coding sequence of rubber oxygenase A (Rox A) from Xanthomonas sp. strain 35Y (Gene bank accession code: AGT20506.1). This 73 kDa protein is an extracellular enzyme that catalyzes oxidative C-C cleavage of poly(cis-1,4-isoprene) to a major product, 12-oxo-4,8-dimethyltrideca-4,8-diene-1-al (ODTD; C15 tri-isoprenoid), with specific activity measured as 0.3 mol min-1 per mg. Found not only in Xanthomonas sp. but also in other Gram-negative clearing zone formers, RoxA is structurally related to cytochrome c peroxidases and its function is associated to two covalently bound heme groups. Although recently characterized by Birke et al (1), the exact enzymatic mechanism of rubber degradation by RoxA has not yet been elucidated. Because Xanthomonas sp. RoxA is exported to the extracellular environment, its open reading frame contains a sequence that codes to a signal peptide flanking its 5’ terminus. We detected this region (amino acid residues from 1 to 20) using signal peptide predictor server (4) (colocar link - http://www.compgen.org/tools/PRED-TAT) and eliminated it to generate part BBa_K1819003 with the coding sequence of RoxA flanked by SacI and NdeI restriction sites. Such non-usual restriction sites may serve for cloning purposes that lead to expression of recombinant protein with no additional amino acid residue(s) between its coding sequence and the fused N-terminal tag. Part BBa_K1819003 was cloned in pSB1C3 plasmid, sequenced and submitted to Registry of Standard Biological Parts.

Lcp - Latex Clearing Protein

Part BBa_K1819001 corresponds to the coding sequence of latex clearing protein (Lcp) from actinomycete Streptomyces sp. strain K30 (GenBank accession code: AAR25849 colocar link ). Other Gram-positive clearing zone bacteria also present this 42 kDa enzyme, which catalyzes rubber cleavage at the cis double bonds to multiple products ranging from C20 tetra-isoprenoid to at least C35 hepta-isoprenoid with measured specific activity of 1.3 mol/min per mg. Lcp contains an oxidized heme-Fe3+ not bound to dioxygen as in RoxA (2). Neither its structure nor its catalysis mechanism were determined until now. Again, because Lcp is secreted by Streptomyces sp, it contains a 5’-signal peptide that was identified using signal peptide predictor server (4) (colocar link - http://www.compgen.org/tools/PRED-TAT). We removed this region from Lcp to generate part BBa_K1819001 flanked by SacI and NdeI restrictions sites. After sequence confirmation, we also submitted it to the Registry.

Back to top