4B15

crystal structure of tamarind chitinase like lectin (TCLL)

Summary for 4B15

• Entry DOI: 10.2210/pdb4b15/pdb
• Related: 4B16
• Descriptor: CHITINASE LIKE LECTIN, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ACETATE ION, ... (6 entities in total)
• Functional Keywords: hydrolase, n-acetyl glucosamine binding lectin, inactive chitinase, class iii chitinase homologs, chilectins
• Biological source: TAMARINDUS INDICA
• Total number of polymer chains: 1
• Total formula weight: 30550.61

Authors

Patil, D.N.,Kumar, P. (deposition date: 2012-07-06, release date: 2013-06-12, Last modification date: 2024-11-20)

Primary citation

Patil, D.N.,Datta, M.,Dev, A.,Dhindwal, S.,Singh, N.,Dasauni, P.,Kundu, S.,Sharma, A.K.,Tomar, S.,Kumar, P.
Structural Investigation of a Novel N-Acetyl Glucosamine Binding Chi-Lectin which Reveals Evolutionary Relationship with Class III Chitinases.
Plos One, 8:63779-, 2013

PubMed Abstract: The glycosyl hydrolase 18 (GH18) family consists of active chitinases as well as chitinase like lectins/proteins (CLPs). The CLPs share significant sequence and structural similarities with active chitinases, however, do not display chitinase activity. Some of these proteins are reported to have specific functions and carbohydrate binding property. In the present study, we report a novel chitinase like lectin (TCLL) from Tamarindus indica. The crystal structures of native TCLL and its complex with N-acetyl glucosamine were determined. Similar to the other CLPs of the GH18 members, TCLL lacks chitinase activity due to mutations of key active site residues. Comparison of TCLL with chitinases and other chitin binding CLPs shows that TCLL has substitution of some chitin binding site residues and more open binding cleft due to major differences in the loop region. Interestingly, the biochemical studies suggest that TCLL is an N-acetyl glucosamine specific chi-lectin, which is further confirmed by the complex structure of TCLL with N-acetyl glucosamine complex. TCLL has two distinct N-acetyl glucosamine binding sites S1 and S2 that contain similar polar residues, although interaction pattern with N-acetyl glucosamine varies extensively among them. Moreover, TCLL structure depicts that how plants utilize existing structural scaffolds ingenuously to attain new functions. To date, this is the first structural investigation of a chi-lectin from plants that explore novel carbohydrate binding sites other than chitin binding groove observed in GH18 family members. Consequently, TCLL structure confers evidence for evolutionary link of lectins with chitinases.

PubMed: 23717482
DOI: 10.1371/JOURNAL.PONE.0063779

Experimental method

X-RAY DIFFRACTION (1.49 Å)