FIG. 3.

Organization diagram of histidine protein kinase genes and proteins in the M. xanthus genome. HPK genes were divided into three categories based on genetic organization. The number of hybrid HPKs is indicated in parentheses for each category. In the second layer, HPKs are divided according to their likely subcellular localization based on the presence (integral membrane) or absence (cytoplasmic) of transmembrane helices. In the third layer, HPK genes are divided according to transcriptional regulation during development. Note that in the third layer, not all HPK genes are included because they are not all present on the M. xanthus DNA microarray or they were not tested by qRT-PCR.