Competence and virulence of Streptococcus pneumoniae: Adc and PsaA mutants exhibit a requirement for Zn and Mn resulting from inactivation of putative ABC metal permeases

摘要: The adcCBA putative operon of Streptococcus pneumoniae, an important human pathogen, was identified in a search for transformation-deficient mutants. It found to exhibit homology ATP-binding cassette (ABC) transport operons encoding streptococcal adhesins such as FimA parasanguis and PsaA S. pneumoniae. latter recently shown be essential virulence judged by intranasal or intraperitoneal challenge mice. We suggested previously that AdcA, together with set 14 proteins, including homologous adhesins, defines new family external solute-binding proteins specific metals. In this work, Northern analysis revealed the existence two adcB-adcA transcripts originating within adcC further upstream, consistent hypothesis adc is operon. Investigation growth psaA mutants synthetic medium addition Zn improved rate former, whereas exhibited absolute requirement added Mn. A psaA-adc double mutant turned out essentially non-viable unless both metals were appropriate ratio. Taken together, these results suggest undocumented pneumoniae also restored near-normal spontaneous transformation cells standard medium. specifically required soon after contact competence-stimulating peptide, revealing unsuspected need removal Mn from resulted deficiency cells. lead us propose Adc ABC-type permease, first protein complex any organism, Psa permease complex.