Lysr Homologs in Acinetobacter: Insights into a Diverse and Prevalent Family of Transcriptional Regulators
Sarah H. Craven, Obidimma C. Ezezika, Cory Momany and Ellen L. Neidle
from: Acinetobacter Molecular Biology (Edited by: Ulrike Gerischer). Caister Academic Press, U.K. (2008)
LysR-type transcriptional regulators (LTTRs) comprise the largest family of homologous regulators in prokaryotes. Family members control functions such as biosynthesis and catabolism, host-microbe interactions, virulence, and antibiotic resistance. This chapter focuses on Acinetobacter LTTRs while citing key examples from other bacteria. Although various experimental approaches continue to elucidate features of LysR-type regulation, many questions remain. Structural studies of full-length LTTRs alone and in complex with effectors and target DNA are typically problematic. Recently, the structures of the effector-binding domains of two LTTRs from Acinetobacter baylyi ADP1, BenM and CatM, were characterized. These structures represent the first, and only examples to date, of LTTRs bound to their natural inducers. Comparisons of these structures with and without effectors highlight conformational changes in LTTRs that participate in signal transduction. BenM and CatM control an intricate regulatory circuit for aromatic compound degradation. This regulon illustrates LTTR functions as well as the utility of ADP1 as a model organism. Natural transformation of this strain facilitates powerful genetic experimental approaches. Additionally, this chapter includes an analysis of 44 LTTRs predicted to be encoded by ADP1. Studies of this important regulatory family continue to improve our understanding of microbial metabolism and facilitate the development of biotechnology applications read more ...