Table 2

Selectivity filters and NPA-boxes

    Ar/R selectivity filter
a

    NPA motifs

Subfamily

Proteinb

H2

H5

LE1

LE2

Loop B

Loop E

Substrate specificity


MIPA

CcMIPA1;1

H

M

M

R

NPM

NPA

AtTIP2;1

H

I

G

R

NPA

NPA

water [58], urea [59], ammonia [60]


MIPB

OlMIPB1;1

Y

L

G

R

NPS

NAA

OrMIPB1;1

Y

F

G

R

NPS

NAA

GLALlac

Y

V

P

R

NPA

NPA

water, glycerol [25]


MIPC

MpMIPC1;1

L

C

G

V

NPT

NPA

MrMIPC1;1

I

T

G

V

NPT

NPA

OtMIPC1;1

V

M

C

P

NPV

NPS

ZmSIP2;1c

S

H

G

S

NPL

NPA

none [61]

OsNIP2;1c

G

S

G

R

NPA

NPA

silicic acid [62], arsenite, antimonite [63]


MIPD

VcMIPD1;1

N

A

A

R

NPA

NPA

CcMIPD1;1

N

A

A

R

NPA

NPA

CnMIPD1;1

N

A

A

R

NPA

NPA

CrMIPD1;1

N

A

A

R

NPA

NPA

glycerol [15]


VcMIPD2;1

T

L

S

R

NPA

NPA

CrMIPD2;1

T

L

S

R

NPL

NPA

CcMIPD3;1

S

T

A

R

NPA

NPA

VcMIPD4;1

N

A

T

H

NPT

NPA

OsTIP4;1

T

T

A

R

NPA

NPA

water, glycerol [29]


MIPE

OrMIPE1;1

F

H

C

R

NPA

NPA

CnMIPE1;1

F

H

C

R

NPA

NPA

CnMIPE1;2

A

H

C

R

NAA

NPT

CnMIPE1;3

F

H

C

R

NPA

NPA

HsAQP5

F

H

C

R

NPA

NPA

water [34]


PIP

CcPIP4;1

F

H

C

R

NPA

NPA

CcPIP4;2

F

H

C

R

NPA

NPA

AtPIP2;3

F

H

T

R

NPA

NPA

water [64]


GIP

PbcvMT325GIP1;1

F

V

I

R

NPA

NPA

CcGIP1;1

F

L

N

R

NPA

NPA

CnGIP1;1

F

I

I

R

NPA

NPA

PpGIP1;1

F

V

P

R

NPA

NPA

glycerol [24]


a) The ar/R filter is defined by four amino acid residues: one in helix 2, one in helix 5 and two in loop E b) Protein names written in bold are MIPs with studied substrate specificities used as reference. They are chosen based on the similarity of their ar/R filter to the ar/R filters of the members within the group c)The MIPCs have very diverse ar/R filters, making it hard to find a reference. Therefore two MIPs with ar/R filters somewhat similar to those of the MIPCs are displayed.

Anderberg et al. BMC Evolutionary Biology 2011 11:110   doi:10.1186/1471-2148-11-110

Open Data