In recent years a new class of opportunistic gram negative pathogens, the Acinetobacter, have become a serious threat both within the community and clinical settings. Although these bacteria have become the focus of increased research, many aspects of their metabolism and transcriptional regulation remain poorly understood. This work details the identification and examination of a novel RNA polymerase binding factor found within the γ proteobacteria, including the Pseudomonas, Klebsiella and Acinetobacter genera. Due to its small size and highly acidic charge, we have called the protein Acidic transcription factor A (AtfA), and have shown it is implicated in a range of clinically and biologically relevant pathways. Deletion of AtfA in the model species Acinetobacter baylyi affects transcription of >500 genes, suggesting a global role for AtfA. Closer examination of the data revealed AtfA was important in the transcription of genes involved in a range of functions including twitching motility, cell division, antibiotic sensitivity, biofilm formation, iron acquisition, virulence and ethanol metabolism. Phenotypic analysis supports these conclusions, with the ΔatfA strain having a large cell phenotype combined with dramatically reduced ethanol metabolism, twitching motility and biofilm formation. Although the mechanism of AtfA action is not yet known, its relative abundance and importance in such a wide range of pathways suggests a versatile role in transcription regulation and may point to the existence of other, as yet unidentified, small regulatory transcription factors.