TY - JOUR AB - The serine protease high-temperature requirement A (HtrA) (DegP) of the human pathogen Streptococcus pyogenes (group A Streptococcus; GAS) is localized to the ExPortal secretory microdomain and is reportedly essential for the maturation of cysteine protease streptococcal pyrogenic exotoxin B (SpeB). Here, we utilize HSC5 (M5 serotype) and the in-frame isogenic mutant HSC5?htrA to determine whether HtrA contributes to the maturation of other GAS virulence determinants. Mutanolysin cell wall extracts and secreted proteins were arrayed by 2-DE and identified by MALDI-TOF PMF analysis. HSC5?htrA had elevated levels of cell wall-associated M protein, whilst the supernatant had higher concentrations of M protein fragments and a reduced amount of mature SpeB protease, compared to wild-type (WT). Western blot analysis and protease assays revealed a delay in the maturation of SpeB in the HSC5?htrA supernatant. HtrA was unable to directly process SpeB zymogen (proSpeB) to the active form in vitro. We therefore conclude that HtrA plays an indirect role in the maturation of cysteine protease SpeB. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA. AU - Cole, JN AU - Aquilina, JA AU - Hains, PG AU - Henningham, A AU - Sriprakash, KS AU - Caparon, MG AU - Nizet, V AU - Kotb, M AU - Cordwell, SJ AU - Djordjevic, SP AU - Walker, MJ DA - 2007/12/01 DO - 10.1002/pmic.200700626 EP - 4498 JO - Proteomics PY - 2007/12/01 SP - 4488 TI - Role of group A Streptococcus HtrA in the maturation of SpeB protease VL - 7 Y1 - 2007/12/01 Y2 - 2024/03/28 ER -