Difference between revisions of "Part:BBa K216008"

Revision as of 15:36, 17 October 2009

bacterial luciferase LuxAB of Xenorhabdus luminescens

This part includes the coding sequences of luxA and luxB of Xenorhabdus luminescens, with their native ribosome binding sites. The dimeric bacterial luciferase LuxAB produces light in the presence of oxygen, FMNH2, and a long chain aldehyde. The aldehyde can be provided by the luxCDE gene products, but if these are not present, n-decanal can be added to cultures.

Usage and Biology

Bacterial luciferase, LuxAB, is a heterodimeric flavoprotein which produces blue light (around 495 nm) through oxidation of a long chain aldehyde (tetradecanal in vivo, but n-decanal is usually used in cases where a substrate needs to be added exogenously). In vivo, the aldehyde is synthesised/regenerated by the LuxCDE gene products. Bacterial luciferase also requires FMNH2, which is provided by an FMN reductase such as LuxG. The normal structure of the operon is luxCDABEG in most bioluminescent bacteria. For use as a reporter system in heterologous hosts such as Escherichia coli, either luxAB alone may be used (in which case decanal must be provided as substrate), or luxCDABE can be used, in which case the organism can synthesise aldehyde itself. It is not necessary to add luxG as E. coli apparently has sufficient endogenous FMN reductase activity to provide this. Based on kinetics, there are two classes of bacterial luciferase; the 'fast decay' type found in Photobacterium, and the 'slow decay' type found in Vibrio and Xenorhabdus. This BioBrick is the luxAB genes of Xenorhabdus (Photorhabdus) luminescens. This is a favourite choice for biosensors, since X. luminescens (unlike all other known bioluminescent bacteria) is a member of the Enterobacteriaceae, hence a close relative of E. coli, and its luxAB has good codon usage for E. coli. Also, X. luminescens is terrestrial rather than marine, and its luciferase is said to be more thermostable than those from other sources (though we can't cite a reference for this).

Sequence and Features

Assembly Compatibility:

10
COMPATIBLE WITH RFC[10]
12
COMPATIBLE WITH RFC[12]
21
COMPATIBLE WITH RFC[21]
23
COMPATIBLE WITH RFC[23]
25
INCOMPATIBLE WITH RFC[25]
Illegal AgeI site found at 530
1000
INCOMPATIBLE WITH RFC[1000]
Illegal SapI site found at 1049

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 This part includes the coding sequences of ''luxA'' and ''luxB'' of ''Xenorhabdus luminescens'', with their native ribosome binding sites. The dimeric bacterial luciferase LuxAB produces light in the presence of oxygen, FMNH2, and a long chain aldehyde. The aldehyde can be provided by the ''luxCDE'' gene products, but if these are not present, n-decanal can be added to cultures.
-<!-- Add more about the biology of this part here
 ===Usage and Biology===
+Bacterial luciferase, LuxAB, is a heterodimeric flavoprotein which produces blue light (around 495 nm) through oxidation of a long chain aldehyde (tetradecanal in vivo, but n-decanal is usually used in cases where a substrate needs to be added exogenously). In vivo, the aldehyde is synthesised/regenerated by the LuxCDE gene products. Bacterial luciferase also requires FMNH2, which is provided by an FMN reductase such as LuxG. The normal structure of the operon is ''luxCDABEG'' in most bioluminescent bacteria. For use as a reporter system in heterologous hosts such as ''Escherichia coli'', either ''luxAB'' alone may be used (in which case decanal must be provided as substrate), or ''luxCDABE'' can be used, in which case the organism can synthesise aldehyde itself. It is not necessary to add ''luxG'' as ''E. coli'' apparently has sufficient endogenous FMN reductase activity to provide this. Based on kinetics, there are two classes of bacterial luciferase; the 'fast decay' type found in ''Photobacterium'', and the 'slow decay' type found in ''Vibrio'' and ''Xenorhabdus''. This BioBrick is the ''luxAB'' genes of ''Xenorhabdus (Photorhabdus) luminescens''. This is a favourite choice for biosensors, since ''X. luminescens'' (unlike all other known bioluminescent bacteria) is a member of the Enterobacteriaceae, hence a close relative of ''E. coli'', and its ''luxAB'' has good codon usage for ''E. coli''. Also, ''X. luminescens'' is terrestrial rather than marine, and its luciferase is said to be more thermostable than those from other sources (though we can't cite a reference for this).
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