Q9AI65 (PALH_ERWRD) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Alpha-glucosidase
EC=3.2.1.20

Gene names

Name:

palH

Organism

Erwinia rhapontici (Pectobacterium rhapontici)

Taxonomic identifier

55212 [NCBI]

Taxonomic lineage

cellular organisms › Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Erwinia

Protein attributes

Sequence length	453 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Alpha-glucosidase with broad specificity. Hydrolyzes maltose, palatinose, maltulose, trehalose, trehalulose, turanose, leucrose, sucrose and maltitol. Is not active against alpha-galactosides, e.g. melibiose, and alpha-mannosides. Shows an obligate requirement for an O-alpha-glycosidic linkage, since it is not able to cleave beta-glycosidic bonds (cellobiose, gentiobiose, lactose, sophorose or laminaribiose). Can not hydrolyze phosphorylated alpha-glucosides derivatives. Seems to be involved in the degradation of palatinose, a sucrose isomer that is formed as a reserve material under conditions of excess carbon availability, sequestered in a form unavailable to competitors such as fungi or the host plant, and whose consumption appears to be postponed until the preferentially metabolized carbon source (e.g. sucrose) is depleted. Ref.1
Catalytic activity	Hydrolysis of terminal, non-reducing (1->4)-linked alpha-D-glucose residues with release of alpha-D-glucose. Ref.2
Cofactor	Binds 1 divalent metal ion per subunit. Mn2+ is the most efficient metal, but to a lesser extent, can also use Co2+, Ca2+, Fe2+, Mg2+, Sr2+, and Ni2+. Can not use Zn2+, Cu2+ or Cr2+. Ref.2 Binds 1 NAD+ per subunit. Ref.2
Enzyme regulation	Is inhibited by EDTA in vitro. Ref.2
Pathway	Glycan degradation; palatinose degradation. Ref.1
Subunit structure	Homotetramer. Ref.2
Induction	Down-regulated by sucrose and up-regulated by palatinose. Ref.1 Ref.2
Sequence similarities	Belongs to the glycosyl hydrolase 4 family.
Biophysicochemical properties	Kinetic parameters: KM=8.58 mM for maltose Ref.2 KM=7.31 mM for maltitol KM=6.59 mM for trehalose KM=3.63 mM for trehalulose KM=22.11 mM for sucrose KM=10.04 mM for turanose KM=1.75 mM for maltulose KM=5.31 mM for leucrose KM=2.52 mM for palatinose KM=180 µM for 4-nitrophenyl-alpha-D-glucopyranoside KM=104 µM for NAD+ KM=47.2 µM for Mn2+ Vmax=1.01 µmol/min/mg enzyme with maltose as substrate Vmax=0.24 µmol/min/mg enzyme with maltitol as substrate Vmax=0.51 µmol/min/mg enzyme with trehalose as substrate Vmax=0.47 µmol/min/mg enzyme with trehalulose as substrate Vmax=0.31 µmol/min/mg enzyme with sucrose as substrate Vmax=0.46 µmol/min/mg enzyme with turanose as substrate Vmax=0.53 µmol/min/mg enzyme with maltulose as substrate Vmax=0.44 µmol/min/mg enzyme with leucrose as substrate Vmax=0.70 µmol/min/mg enzyme with palatinose as substrate Vmax=6.01 µmol/min/mg enzyme with 4-nitrophenyl-alpha-D-glucopyranoside as substrate
Mass spectrometry	Molecular mass is 50216 Da from positions 2 - 453. Determined by ESI. Ref.2
Sequence caution	The sequence AAK28734.1 differs from that shown. Reason: Erroneous initiation.

Ontologies

Keywords
Biological process	Carbohydrate metabolism
Ligand	Calcium Cobalt Iron Magnesium Manganese Metal-binding NAD Nickel
Molecular function	Glycosidase Hydrolase
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	carbohydrate metabolic process Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	maltose alpha-glucosidase activity Inferred from electronic annotation. Source: EC metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW nucleotide binding Inferred from electronic annotation. Source: InterPro oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Initiator methionine	1	1	Removed Ref.2
	Chain	2 – 453	452	Alpha-glucosidase		PRO_0000389548
Regions
	Nucleotide binding	3 – 69	67	NAD By similarity
Sites
	Active site	172	1	Proton donor By similarity
	Metal binding	171	1	Manganese By similarity
	Metal binding	201	1	Manganese By similarity
	Binding site	149	1	Substrate By similarity
Experimental info
	Mutagenesis	173	1	E → S: Loss of catalytic activity. Ref.2
	Mutagenesis	174	1	I → V: No effect on catalytic activity. Ref.2

Sequences

	Sequence		Length	Mass (Da)
	Q9AI65 [UniParc]. Last modified November 24, 2009. Version 2. Checksum: 64B178085AE436AC	FASTA	453	50,341
	10 20 30 40 50 60 MATKIVLVGA GSAQFGYGTL GDIFQSRALY GSEIILHDIN PVALAVTEKT AKDFLAKEDL 70 80 90 100 110 120 PFIVSATTDR RTALRGAEFV IISIEVGDRF ALWDLDWQIP QQYGIQQVYG ENGGPGGLFH 130 140 150 160 170 180 SLRIIPPILD ICADVADICP DAWIFNYSNP MSRICTTVHR RFPELNFVGM CHEIASLERY 190 200 210 220 230 240 LPEMLNTSFD NLSLRAGGLN HFSVLLDARY KDSGKDAYAD VRAKAPDYFA SLPGYSDILA 250 260 270 280 290 300 YTRQHGKLVD TEGSTERHAL GGKDSSYPWA DRTLFKEILE KFHCMPITVD SHFGEYISWA 310 320 330 340 350 360 GEVSDHRGIL DFYTFYRNYL GGVQPKIELK LKERVVSIME GILTDSGYEE AAVNIPNRGF 370 380 390 400 410 420 IKQLPEFIAV EVPAIIDRKG VHGIQVDIPP GIGGLLSNQI AIHDLTAEAI IAGSRDLVIQ 430 440 450 ALLVDSVNNQ CRAIPELVDV MISRQQPWLN YLK

References

[1]

"Cloning and characterization of the gene cluster for palatinose metabolism from the phytopathogenic bacterium Erwinia rhapontici." Boernke F., Hajirezaei M., Sonnewald U. J. Bacteriol. 183:2425-2430(2001) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION IN PALATINOSE METABOLISM, PATHWAY, INDUCTION. Strain: ATCC 29283 / DSM 4484 / NCPPB 1578 / ICPB ER 102.

[2]

"Evolution and biochemistry of family 4 glycosidases: implications for assigning enzyme function in sequence annotations." Hall B.G., Pikis A., Thompson J. Mol. Biol. Evol. 26:2487-2497(2009) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 2-26, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, COFACTOR, ENZYME REGULATION, KINETIC PARAMETERS, MASS SPECTROMETRY, SUBUNIT, MUTAGENESIS OF GLU-173 AND ILE-174. Strain: ATCC 29283 / DSM 4484 / NCPPB 1578 / ICPB ER 102.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF279280 Genomic DNA. Translation: AAK28734.1. Different initiation.
3D structure databases
ProteinModelPortal	Q9AI65.
ModBase	Search...
Protein family/group databases
CAZy	GH4. Glycoside Hydrolase Family 4.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Enzyme and pathway databases
UniPathway	UPA01004.
Family and domain databases
Gene3D	3.40.50.720. 1 hit. 3.90.110.10. 1 hit.
InterPro	IPR001088. Glyco_hydro_4. IPR022616. Glyco_hydro_4_C. IPR015955. Lactate_DH/Glyco_Ohase_4_C. IPR016040. NAD(P)-bd_dom. [Graphical view]
Pfam	PF02056. Glyco_hydro_4. 1 hit. PF11975. Glyco_hydro_4C. 1 hit. [Graphical view]
PRINTS	PR00732. GLHYDRLASE4.
SUPFAM	SSF56327. Lactate_DH/Glyco_hydro_4_C. 1 hit.
PROSITE	PS01324. GLYCOSYL_HYDROL_F4. False negative. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

PALH_ERWRD

Accession

Primary (citable) accession number: Q9AI65

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 24, 2009
Last sequence update:	November 24, 2009
Last modified:	April 3, 2013
This is version 43 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program