Structure and function of RNase AS, a polyadenylate-specific exoribonuclease affecting mycobacterial virulence in vivo.
The cell-envelope of Mycobacterium tuberculosis plays a key role in bacterial virulence and antibiotic resistance. Little is known about the molecular mechanisms of regulation of cell-envelope formation. Here, we elucidate functional and structural properties of RNase AS, which modulates M. tuberculosis cell-envelope properties and strongly impacts bacterial virulence in vivo. The structure of RNase AS reveals a resemblance to RNase T from Escherichia coli, an RNase of the DEDD family involved in RNA maturation. We show that RNase AS acts as a 3'-5'-exoribonuclease that specifically hydrolyzes adenylate-containing RNA sequences. Also, crystal structures of complexes with AMP and UMP reveal the structural basis for the observed enzyme specificity. Notably, RNase AS shows a mechanism of substrate recruitment, based on the recognition of the hydrogen bond donor NH2 group of adenine. Our work opens a field for the design of drugs able to reduce bacterial virulence in vivo.
Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, I-80134 Naples, Italy.
Maria
M
Romano
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Robert
R
van de Weerd
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Femke C C
FC
Brouwer
Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, I-80134 Naples, Italy.
Giovanni N
GN
Roviello
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Ruben
R
Lacroix
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Marion
M
Sparrius
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Gunny
G
van den Brink-van Stempvoort
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Janneke J
JJ
Maaskant
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Astrid M
AM
van der Sar
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands. Electronic address: bj.appelmelk@vumc.nl.
Ben J
BJ
Appelmelk
Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands.
Jeroen J
JJ
Geurtsen
Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, I-80134 Naples, Italy. Electronic address: rita.berisio@cnr.it.
Rita
R
Berisio
D000225:Adenine; D000249:Adenosine Monophosphate / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D018360:Crystallography, X-Ray; D004625:Embryo, Nonmammalian / Q000382:microbiology; D005095:Exoribonucleases / Q000737:chemistry; D055786:Gene Knockout Techniques; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009154:Mutation; D019910:Mycobacterium marinum / Q000235:genetics / Q000472:pathogenicity; D009169:Mycobacterium tuberculosis / Q000201:enzymology / Q000472:pathogenicity*; D011061:Poly A / Q000378:metabolism; D055503:Protein Multimerization; D012260:Ribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity; D014542:Uridine Monophosphate / Q000737:chemistry / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology / Q000382:microbiology
D001426:Bacterial Proteins; D011061:Poly A; D000249:Adenosine Monophosphate; D014542:Uridine Monophosphate; D005095:Exoribonucleases; D012260:Ribonucleases; C042081:exoribonuclease T; D000225:Adenine