Structure of putative 4-amino-4-deoxychorismate lyase from Thermus thermophilus HB8.
The pyridoxal 5'-phosphate-dependent enzyme 4-amino-4-deoxychorismate lyase converts 4-amino-4-deoxychorismate to p-aminobenzoate and pyruvate in one of the crucial steps in the folate-biosynthesis pathway. The primary structure of the hypothetical protein TTHA0621 from Thermus thermophilus HB8 suggests that TTHA0621 is a putative 4-amino-4-deoxychorismate lyase. Here, the crystal structure of TTHA0621 is reported at 1.93 A resolution. The asymmetric unit contained four NCS molecules related by 222 noncrystallographic symmetry, in which the formation of intact dimers may be functionally important. The cofactor pyridoxal 5'-phosphate (PLP) binds to the protein in the large cleft formed by the N-terminal and C-terminal domains of TTHA0621. The high structural similarity and the conservation of the functional residues in the catalytic region compared with 4-amino-4-deoxychorismate lyase (PabC; EC 4.1.3.38) from Escherichia coli suggest that the TTHA0621 protein may also possess 4-amino-4-deoxychorismate lyase activity.
Padmanabhan
Balasundaram
B
Systems and Structural Biology Center, Yokohama Institute, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama 230-0045, Japan. bpadmanabhan@hotmail.com
Bessho
Yoshitaka
Y
Ebihara
Akio
A
Antonyuk
Svetlana V
SV
Ellis
Mark J
MJ
Strange
Richard W
RW
Kuramitsu
Seiki
S
Watanabe
Nobuhisa
N
Hasnain
S Samar
SS
Yokoyama
Shigeyuki
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005798:Genes, Bacterial; D008190:Lyases / Q000737:chemistry / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D007652:Oxo-Acid-Lyases / Q000737:chemistry* / Q000235:genetics; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein; D016963:Thermus thermophilus / Q000201:enzymology* / Q000235:genetics
D001426:Bacterial Proteins; D011994:Recombinant Proteins; C079404:PabC protein, Bacteria; D008190:Lyases; D007652:Oxo-Acid-Lyases; C066600:aminodeoxychorismate lyase