Structure of PDB 4xb3 Chain A

Receptor sequence

>4xb3A (length=536) Species: 210007 (Streptococcus mutans UA159)

MQKHWWHKATVYQIYPKSFMDTNGDGIGDLKGITSKLDYLQKLGVMAIWL
SPVYDSPMDDNGYDIANYEAIADIFGNMADMDNLLTQAKMRGIKIIMDLV
VNHTSDEHAWFIEAREHPDSSERDYYIWCDQPNDLESIFGGSAWQYDDKS
DQYYLHFFSKKQPDLNWENANLRQKIYDMMNFWIDKGIGGFRMDVIDMIG
KIPAQHIVSNGPKLHAYLKEMNAASFGQHDLLTVGQTWGATPEIAKQYSN
PVNHELSMVFQFEHIGLQHKPEAPKWDYVKELNVPALKTIFNKWQTELEL
GQGWNSLFWNNHDLPRVLSIWGNTGKYREKSAKALAILLHLMRGTPYIYQ
GEEIGMTNYPFKDLNELDDIESLNYAKEAFTNGKSMETIMDSIRMIGRDN
ARTPMQWDASQNAGFSTADKTWLPVNPNYKDINVQAALKNSNSIFYTYQQ
LIQLRKENDWLVDADFELLPTADKVFAYLRKVREERYLIVVNVSDQEEVL
EIDVDKQETLISNTNESAALANHKLQPWDAFCIKIL

3D structure

• PDB: 4xb3 Structural insights into the catalytic reaction that is involved in the reorientation of Trp238 at the substrate-binding site in GH13 dextran glucosidase
• Chain: A
• Resolution: 2.093 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): D98 R192 D194 Q236 H312 D313
• Catalytic site (residue number reindexed from 1): D98 R192 D194 Q236 H312 D313
• Enzyme Commision number: 3.2.1.70: glucan 1,6-alpha-glucosidase.

Interaction with ligand

Site #	Ligand	Ligand chain	Binding residues on receptor (original residue number in PDB)	Binding residues on receptor (residue number reindexed from 1)	Binding affinity
BS01	CA	A	D148 D151	D148 D151
BS02	CA	A	D21 N23 D25 I27 D29	D21 N23 D25 I27 D29
BS03	CA	A	K439 S441	K439 S441

Gene Ontology

Molecular Function

• GO:0004556 alpha-amylase activity
• GO:0016798 hydrolase activity, acting on glycosyl bonds
• GO:0043896 glucan 1,6-alpha-glucosidase activity

Biological Process

• GO:0005975 carbohydrate metabolic process
• GO:0009313 oligosaccharide catabolic process

Cellular Component

• GO:0005737 cytoplasm

External links

• PDB: RCSB:4xb3, PDBe:4xb3, PDBj:4xb3
• PDBsum: 4xb3
• PubMed: 25595454
• UniProt: Q99040|DEXB_STRMU Glucan 1,6-alpha-glucosidase (Gene Name=dexB)