41. Linear layout of lambda phage genome with major operons , promoter regions and capsid coding genes. 42. Operons can also be positively controlled.43. Bacterial operons are polycistronic transcripts that are able to produce multiple proteins from one mRNA transcript. 44. An example of a cis-acting regulatory sequence is the operator in the lac operon . 45. The total range of trp operon regulation is about 700 X ( on / off ). 46. It should also be understood that the lac operon is affected by the presence of glucose. 47. This causes the anti-terminator loop to form and the tryptophan operon to be transcribed. 48. This operon encodes the translation initiation factor IF-3 and ribosomal proteins L35 and L20. 49. The gene encoding the archease ( PAB1946 ) is located in a bicistronic operon immediately complex. 50. The ArsD family consists of several bacterial arsenical resistance operon trans-acting repressor ArsD proteins.
