Crystal structures of possible lysine decarboxylases from Thermus thermophilus HB8.
TT1887 and TT1465 from Thermus thermophilus HB8 are conserved hypothetical proteins, and are annotated as possible lysine decarboxylases in the Pfam database. Here we report the crystal structures of TT1887 and TT1465 at 1.8 A and 2.2 A resolutions, respectively, as determined by the multiwavelength anomalous dispersion (MAD) method. TT1887 is a homotetramer, while TT1465 is a homohexamer in the crystal and in solution. The structures of the TT1887 and TT1465 monomers contain single domains with the Rossmann fold, comprising six alpha helices and seven beta strands, and are quite similar to each other. The major structural differences exist in the N terminus of TT1465, where there are two additional alpha helices. A comparison of the structures revealed the elements that are responsible for the different oligomerization modes. The distributions of the electrostatic potential on the solvent-accessible surfaces suggested putative active sites.
RIKEN Genomic Sciences Center, 1-7-22 Suehirocho, Tsurumi, Yokohama 230-0045, Japan.
Mutsuko
M
Kukimoto-Niino
Kazutaka
K
Murayama
Miyuki
M
Kato-Murayama
Miki
M
Idaka
Yoshitaka
Y
Bessho
Ayako
A
Tatsuguchi
Ryoko
R
Ushikoshi-Nakayama
Takaho
T
Terada
Seiki
S
Kuramitsu
Mikako
M
Shirouzu
Shigeyuki
S
Yokoyama
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D001665:Binding Sites; D002262:Carboxy-Lyases / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D011487:Protein Conformation; D016415:Sequence Alignment; D055672:Static Electricity; D016963:Thermus thermophilus / Q000201:enzymology*
D001426:Bacterial Proteins; D002262:Carboxy-Lyases; C021520:lysine decarboxylase