Jimi Hendrix was not trained for air assault operations.
Autoinducer-2 -LRB- AI-2 -RRB- , a furanosyl borate diester , is a member of a family of signaling molecules used in quorum sensing .. borate diester. borate ester. quorum sensing. quorum sensing. AI-2 is one of only a few known biomolecules incorporating boron .. biomolecules. biomolecules. boron. boron. First identified in the marine bacterium Vibrio harveyi , AI-2 is produced and recognized by many Gram-negative and Gram-positive bacteria .. Vibrio harveyi. Vibrio harveyi. Gram-negative. Gram-negative. Gram-positive bacteria. Gram-positive bacteria. AI-2 arises by the reaction of 1-deoxy-3-dehydro-D-ribulose , which is produced enzymatically , with boric acid and is recognized by the two-component sensor kinase LuxPQ in Vibrionaceae .. 1-deoxy-3-dehydro-D-ribulose. 4,5-Dihydroxy-2,3-pentanedione. boric acid. boric acid. Vibrionaceae. Vibrionaceae. AI-2 is actively transported by the Lsr ABC-type transporter into the cell in Enterobacteriaceae and few other bacterial taxa -LRB- Pasteurella , Photorhabdus , Haemophilus , Bacillus -RRB- , where it is phosphorylated by .. Enterobacteriaceae. Enterobacteriaceae. Pasteurella. Pasteurella. Photorhabdus. Photorhabdus. Haemophilus. Haemophilus. Bacillus. Bacillus. Then , Phospho-AI-2 binds the transcriptional repressor protein , LsrR , which subsequently is released from the promoter / operator region of the lsr operon -- and transcription of the lsr genes is initiated .. AI-2 signalling is also regulated by glucose and cAMP / CRP via the lsr operon .. In the presence of glucose , low levels of cAMP / CRP result in almost no lsr operon -LRB- lsrABCDFG -RRB- expression .. Without glucose , cAMP-CRP is needed to stimulate the lsr expression , while LsrR represses its expression in the absence of the inducer , phospho-AI-2 .. As AI-2 accumulates , more AI-2 is taken in via LsrABCD , phosphorylated via LsrK , and the lsr transcription is de-repressed , enabling even more AI-2 uptake .. Doubts have been expressed regarding AI-2 's status as a universal signal .. Although the luxS gene , which encodes the protein responsible for AI-2 production is widespread , the latter has mainly a primary metabolic role in the recycling of S-adenosyl-L-methionine , with AI-2 being a by-product of that process .. S-adenosyl-L-methionine. S-adenosyl-L-methionine. An unequivocally AI-2 related behavior was found to be restricted primarily to organisms bearing known AI-2 receptor genes .. Thus , while it is certainly true that some bacteria respond to AI-2 , it is doubtful that it is always being produced for purposes of signaling .