Other regulons share a conserved overall strategy but include additional regulator components to integrate additional regulatory signals, or show transfer of regulation from one regulator to another, or rewiring via evolution of combinatorial interactions between transcription factors [ 36- 38].
Moreover, the number of ribosomal operons (3) and regulatory systems in both CS-505 and D9 (81 and 75 sensor-regulator components, respectively), is more similar to that of Synechocystis sp. PCC 6803 (3 ribosomal operons and 89 sensor-regulator systems), to that of the filamentous Anabaena (4 ribosomal operons and 175 sensor-regulator systems).
The second transposon, Tn 552, encodes an inducible β-lactamase and its regulator components.
They are distributed as 21 fused enzymes, 9 fused regulator components, 4 fused ABC transporter components, 4 fused phosphotransferase system (PTS) components and 3 mixed enzyme-regulator combinations.
For some regulons the regulator components are conserved but exhibit functional reassignment and rewired circuitry, resulting in rearrangements of transcriptional networks [ 35].
This was caused by the fact that several domains of the sensor and regulator components of signal transduction systems are highly conserved.
The genome of A. arilaitensis Re117 encodes 253 proteins with possible function in gene regulation (one-component regulators, two-component regulators, sigma and anti-sigma factors), representing 7.4% of the CDSs.
The recent demonstration that the expression of glnR and of some of the GlnR-regulated genes of S. coelicolor is subject to repression by PhoB, the response regulator component of the phosphate sensing system [ 13], highlights the cross-talk that can occur between regulatory systems involved in the global co-ordination of primary metabolism.
BCAM2837, a pseudogene in sequenced type strain J2315, is annotated as the response regulator component of a two-component regulatory system.
These systems consist of a sensor kinase (component 1) which autophosphorylates histidine, then transphosphorylates a conserved aspartate of its cognate transcriptional regulator (component 2).
