Structural and Enzymatic Characterization of a cAMP-Dependent Diguanylate Cyclase from Pathogenic Leptospira Species

Author(s)

da Costa Vasconcelos, Fernanda Nogales ; Maciel, Nikolas Koshiyama ; Favaro, Denize Cristina ; de Oliveira, Luciana Coutinho ; Barbosa, Angela Silva ; Salinas, Roberto Kopke ; de Souza, Robson Francisco ; Farah, Chuck Shaker ; Guzzo, Cristiane Rodrigues

• Document type: Journal article
• Source: Journal of Molecular Biology; v. 429, n. 15, p. 2337-2352, JUL 21 2017.
• Web of Science Citations: 6

Abstract

Leptospira interrogans serovar Copenhageni is a human pathogen that causes leptospirosis, a worldwide zoonosis. The L. interrogans genome codes for a wide array of potential diguanylate cyclase (DGC) enzymes with characteristic GGDEF domains capable of synthesizing the cyclic dinucleotide c-di-GMP, known to regulate transitions between different cellular behavioral states in bacteria. Among such enzymes, LIC13137 (Lcd1), which has an N-terminal cGMP-specific phosphodiesterases, adenylyl cyclases, and FhIA (GAF) domain and a C-terminal GGDEF domain, is notable for having close orthologs present only in pathogenic Leptospira species. Although the function and structure of GGDEF and GAF domains have been studied extensively separately, little is known about enzymes with the GAF-GGDEF architecture. In this report, we address the question of how the GAF domain regulates the DGC activity of Lcd1. The full-length Lcd1 and its GAF domain form dimers in solution. The GAF domain binds specifically cAMP (K-D of 0.24 mu M) and has an important role in the regulation of the DGC activity of the GGDEF domain. Lcd1 DGC activity is negligible in the absence of cAMP and is significantly enhanced in its presence (specific activity of 0.13 s(-1)). The crystal structure of the Lcd1 GAF domain in complex with cAMP provides valuable insights toward explaining its specificity for cAMP and pointing to possible mechanisms by which this cyclic nucleotide regulates the assembly of an active DGC enzyme. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 13/18664-2 - Study of Type II secretion system and the molecular bases involved c-di-GMP signaling on Leptospira interrogans Serovar Copenhageni
• Grantee: Robson Francisco de Souza
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/06650-7 - Functional and structural study of LIC13137 and LIC11300 of Leptospira interrogans serovar copenhageni
• Grantee: Nikolas Koshiyama Maciel
• Support Opportunities: Scholarships in Brazil - Scientific Initiation