The biogenesis of c-type cytochromes (Cytc) is a process that in Gram-negative bacteria demands the coordinated action of different periplasmic proteins (CcmA-I), whose specific roles are still being investigated. Activities of Ccm proteins span from the chaperoning of heme b in the periplasm to the specific reduction of oxidized apocytochrome (apoCyt) cysteine residues and to chaperoning and recognition of the unfolded apoCyt before covalent attachment of the heme to the cysteine thiols can occur. We present here the functional characterization of the periplasmic domain of CcmI from the pathogen Pseudomonas aeruginosa (Pa-CcmI*). Pa-CcmI* is composed of a TPR domain and a peculiar C-terminal domain. Pa-CcmI* fulfills both the ability to recognize and bind to P. aeruginosa apo-cytochrome c551 (Pa-apoCyt) and a chaperoning activity towards unfolded proteins, as it prevents citrate synthase aggregation in a concentration-dependent manner. Equilibrium and kinetic experiments with Pa-CcmI*
Recognition and binding of apocytochrome c to P. aeruginosa CcmI, a component of cytochrome c maturation machinery / DI SILVIO, Eva; DI MATTEO, Adele; Malatesta, Francesco; TRAVAGLINI ALLOCATELLI, Carlo. - In: BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS. - ISSN 1570-9639. - STAMPA. - 1834:8(2013), pp. 1554-1561. [10.1016/j.bbapap.2013.04.027]
Recognition and binding of apocytochrome c to P. aeruginosa CcmI, a component of cytochrome c maturation machinery.
DI SILVIO, EVA;DI MATTEO, Adele;MALATESTA, FRANCESCO;TRAVAGLINI ALLOCATELLI, Carlo
2013
Abstract
The biogenesis of c-type cytochromes (Cytc) is a process that in Gram-negative bacteria demands the coordinated action of different periplasmic proteins (CcmA-I), whose specific roles are still being investigated. Activities of Ccm proteins span from the chaperoning of heme b in the periplasm to the specific reduction of oxidized apocytochrome (apoCyt) cysteine residues and to chaperoning and recognition of the unfolded apoCyt before covalent attachment of the heme to the cysteine thiols can occur. We present here the functional characterization of the periplasmic domain of CcmI from the pathogen Pseudomonas aeruginosa (Pa-CcmI*). Pa-CcmI* is composed of a TPR domain and a peculiar C-terminal domain. Pa-CcmI* fulfills both the ability to recognize and bind to P. aeruginosa apo-cytochrome c551 (Pa-apoCyt) and a chaperoning activity towards unfolded proteins, as it prevents citrate synthase aggregation in a concentration-dependent manner. Equilibrium and kinetic experiments with Pa-CcmI*I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
