4GBD

Crystal Structure Of Adenosine Deaminase From Pseudomonas Aeruginosa Pao1 with bound Zn and methylthio-coformycin

Summary for 4GBD

• Entry DOI: 10.2210/pdb4gbd/pdb
• Descriptor: Putative uncharacterized protein, (8R)-3-(5-S-methyl-5-thio-beta-D-ribofuranosyl)-3,6,7,8-tetrahydroimidazo[4,5-d][1,3]diazepin-8-ol, ZINC ION, ... (5 entities in total)
• Functional Keywords: deaminase, methyltihoadenosine, lyase
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 2
• Total formula weight: 101804.86

Authors

Ho, M.,Guan, R.,Almo, S.C.,Schramm, V.L. (deposition date: 2012-07-27, release date: 2013-06-12, Last modification date: 2024-02-28)

Primary citation

Guan, R.,Ho, M.C.,Frohlich, R.F.,Tyler, P.C.,Almo, S.C.,Schramm, V.L.
Methylthioadenosine deaminase in an alternative quorum sensing pathway in Pseudomonas aeruginosa.
Biochemistry, 51:9094-9103, 2012

PubMed Abstract: Pseudomonas aeruginosa possesses an unusual pathway for 5'-methylthioadenosine (MTA) metabolism involving deamination to 5'-methylthioinosine (MTI) followed by N-ribosyl phosphorolysis to hypoxanthine and 5-methylthio-α-d-ribose 1-phosphate. The specific MTI phosphorylase of P. aeruginosa has been reported [Guan, R., Ho, M. C., Almo, S. C., and Schramm, V. L. (2011) Biochemistry 50, 1247-1254], and here we characterize MTA deaminase from P. aeruginosa (PaMTADA). Genomic analysis indicated the PA3170 locus to be a candidate for MTA deaminase (MTADA). Protein encoded by PA3170 was expressed and shown to deaminate MTA with 40-fold greater catalytic efficiency for MTA than for adenosine. The k(cat)/K(m) value of 1.6 × 10(7) M(-1) s(-1) for MTA is the highest catalytic efficiency known for an MTA deaminase. 5'-Methylthiocoformycin (MTCF) is a 4.8 pM transition state analogue for PaMTADA but causes no significant inhibition of human adenosine deaminase or MTA phosphorylase. MTCF is permeable to P. aeruginosa and exhibits an IC(50) of 3 nM on cellular PaMTADA activity. PaMTADA is the only activity in P. aeruginosa extracts to act on MTA. MTA and 5-methylthio-α-d-ribose are involved in quorum sensing pathways; thus, PaMTADA is a potential target for quorum sensing. The crystal structure of PaMTADA in complex with MTCF shows the transition state mimic 8(R)-hydroxyl group in contact with a catalytic site Zn(2+), the 5'-methylthio group in a hydrophobic pocket, and the transition state mimic of the diazepine ring in contact with a catalytic site Glu.

PubMed: 23050701
DOI: 10.1021/bi301062y

Experimental method

X-RAY DIFFRACTION (1.975 Å)