cDNA cloning and 1.75 A crystal structure determination of PPL2, an endochitinase and N-acetylglucosamine-binding hemagglutinin from Parkia platycephala seeds.
Parkia platycephala lectin 2 was purified from Parkia platycephala (Leguminosae, Mimosoideae) seeds by affinity chromatography and RP-HPLC. Equilibrium sedimentation and MS showed that Parkia platycephala lectin 2 is a nonglycosylated monomeric protein of molecular mass 29 407+/-15 Da, which contains six cysteine residues engaged in the formation of three intramolecular disulfide bonds. Parkia platycephala lectin 2 agglutinated rabbit erythrocytes, and this activity was specifically inhibited by N-acetylglucosamine. In addition, Parkia platycephala lectin 2 hydrolyzed beta(1-4) glycosidic bonds linking 2-acetoamido-2-deoxy-beta-D-glucopyranose units in chitin. The full-length amino acid sequence of Parkia platycephala lectin 2, determined by N-terminal sequencing and cDNA cloning, and its three-dimensional structure, established by X-ray crystallography at 1.75 A resolution, showed that Parkia platycephala lectin 2 is homologous to endochitinases of the glycosyl hydrolase family 18, which share the (betaalpha)8 barrel topology harboring the catalytic residues Asp125, Glu127, and Tyr182.
Cavada
Benildo S
BS
BioMol-Laboratory, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil. bscavada@ufc.br
Moreno
Frederico B B
FB
da Rocha
Bruno A M
BA
de Azevedo
Walter F
WF
Castellón
Rolando E R
RE
Goersch
Georg V
GV
Nagano
Celso S
CS
de Souza
Emmanuel P
EP
Nascimento
Kyria S
KS
Radis-Baptista
Gandhi
G
Delatorre
Plínio
P
Leroy
Yves
Y
Toyama
Marcos H
MH
Pinto
Vicente P T
VP
Sampaio
Alexandre H
AH
Barettino
Domingo
D
Debray
Henri
H
Calvete
Juan J
JJ
Sanz
Libia
L
D000117:Acetylglucosamine / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002688:Chitinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003460:Crystallization; D018360:Crystallography, X-Ray; D018076:DNA, Complementary / Q000302:isolation & purification; D007887:Fabaceae / Q000201:enzymology* / Q000235:genetics; D006388:Hemagglutinins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D012639:Seeds / Q000201:enzymology* / Q000235:genetics
D018076:DNA, Complementary; D006388:Hemagglutinins; D037121:Plant Lectins; D002688:Chitinases; D000117:Acetylglucosamine