luxR solo homolog in Novosphingobium sp. PP1Y and its distinctive gene neighborhood. (A) Visualization of the genomic region within 2,000 bp of various well-established luxR solo homologs. avhR, NC_011989: 3,701,490 - 3,706,230; aviR, NC_011989: 774,222 – 778,914; bisR, AY177751: 3,858 – 8,598; expR, HE995405: 3,197,265 – 3,202,005; qscR, NC_002516: 2,067,490 – 2,072,203; nesR, NC_020528: 3,032,865 – 3,037,713 (B) Phylogenetic clustering of various LuxR homologs identified in the genus Novosphingobium. NovR solos were shown in boxed lines. (C) 20-kb genomic fragment of strain PP1Y showing the presence of various mobile elements upstream of the novR solo and tBLASTx comparison of the presumably fragmented transposase genes immediately upstream of novR solo with two complete transposase genes and also a genomic region of Rhodospirillum photometricum.