CaUC01G007190 (gene) Watermelon (USVL246-FR2) v1

Overview
NameCaUC01G007190
Typegene
OrganismCitrullus amarus (Watermelon (USVL246-FR2) v1)
DescriptionPurple acid phosphatase
LocationCiama_Chr01: 8079596 .. 8079916 (-)
RNA-Seq ExpressionCaUC01G007190
SyntenyCaUC01G007190
Sequences
The following sequences are available for this feature:

Gene sequence (with intron)

Legend: exonCDSpolypeptide
Hold the cursor over a type above to highlight its positions in the sequence below.
ATGGACGCCGCCGCTTCCAACCGCCCTGTCCGACTTCTCCTCTGCCTTGTTATTGCGTTAAGCGGCGTCCTTTTTACTGATGCGGAGCTTCGGCGATTTCCCCATCCCTCCAAAGACGACGGCTCTCTCAGCCTTCTGGTCGTCGGAGACTGGGGACGAAACGGAGAATACAACCAATCTCAAGTTGCCCTTCAGGTCCTCTCTCTCTCTCCTACAACCAATCTCTGTAATTTAGTCATTAAACTTTTATTAATAACAATTTCAATCTCTATACTTTCTATACTTCCAATTACCGTTATTGTTACTAATAAGTTTACATAA

mRNA sequence

ATGGACGCCGCCGCTTCCAACCGCCCTGTCCGACTTCTCCTCTGCCTTGTTATTGCGTTAAGCGGCGTCCTTTTTACTGATGCGGAGCTTCGGCGATTTCCCCATCCCTCCAAAGACGACGGCTCTCTCAGCCTTCTGGTCGTCGGAGACTGGGGACGAAACGGAGAATACAACCAATCTCAAGTTGCCCTTCAGGTCCTCTCTCTCTCTCCTACAACCAATCTCTGTAATTTAGTCATTAAACTTTTATTAATAACAATTTCAATCTCTATACTTTCTATACTTCCAATTACCGTTATTGTTACTAATAAGTTTACATAA

Coding sequence (CDS)

ATGGACGCCGCCGCTTCCAACCGCCCTGTCCGACTTCTCCTCTGCCTTGTTATTGCGTTAAGCGGCGTCCTTTTTACTGATGCGGAGCTTCGGCGATTTCCCCATCCCTCCAAAGACGACGGCTCTCTCAGCCTTCTGGTCGTCGGAGACTGGGGACGAAACGGAGAATACAACCAATCTCAAGTTGCCCTTCAGGTCCTCTCTCTCTCTCCTACAACCAATCTCTGTAATTTAGTCATTAAACTTTTATTAATAACAATTTCAATCTCTATACTTTCTATACTTCCAATTACCGTTATTGTTACTAATAAGTTTACATAA

Protein sequence

MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQSQVALQVLSLSPTTNLCNLVIKLLLITISISILSILPITVIVTNKFT
Homology
BLAST of CaUC01G007190 vs. NCBI nr
Match: XP_016903715.1 (PREDICTED: purple acid phosphatase 4-like [Cucumis melo])

HSP 1 Score: 108.6 bits (270), Expect = 3.3e-20
Identity = 59/77 (76.62%), Postives = 64/77 (83.12%), Query Frame = 0

Query: 3  AAASNRPVRLL-LCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQSQ 62
          AAASN  VRLL LCL+IALSGVL T A+L RF HPSKDDGSLSLLV+GDWGRNG+YNQS+
Sbjct: 2  AAASNHIVRLLILCLLIALSGVLLTRADLPRFAHPSKDDGSLSLLVLGDWGRNGDYNQSE 61

Query: 63 VALQVLSLSPTTNLCNL 79
          VALQVL LS T  L  L
Sbjct: 62 VALQVLPLSYTPPLFTL 78

BLAST of CaUC01G007190 vs. NCBI nr
Match: XP_022939885.1 (purple acid phosphatase 3-like [Cucurbita moschata])

HSP 1 Score: 103.2 bits (256), Expect = 1.4e-18
Identity = 51/66 (77.27%), Postives = 56/66 (84.85%), Query Frame = 0

Query: 1  MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQS 60
          MDA ASNR V LLL ++IA SGV+FT AEL+RF HP KDDGSLSLLVVGDWGR GEYNQS
Sbjct: 1  MDADASNRRVGLLLWVIIAFSGVVFTAAELQRFSHPPKDDGSLSLLVVGDWGRKGEYNQS 60

Query: 61 QVALQV 67
          QVA Q+
Sbjct: 61 QVAAQM 66

BLAST of CaUC01G007190 vs. NCBI nr
Match: XP_023550610.1 (purple acid phosphatase 17-like [Cucurbita pepo subsp. pepo])

HSP 1 Score: 103.2 bits (256), Expect = 1.4e-18
Identity = 51/66 (77.27%), Postives = 57/66 (86.36%), Query Frame = 0

Query: 1  MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQS 60
          MDAAASNR V LLL +VIA SGV+FT AEL+RF HP KDDGSL+LLVVGDWGR GEYNQS
Sbjct: 31 MDAAASNRRVGLLLWVVIAFSGVVFTAAELQRFSHPPKDDGSLTLLVVGDWGRKGEYNQS 90

Query: 61 QVALQV 67
          +VA Q+
Sbjct: 91 KVAAQM 96

BLAST of CaUC01G007190 vs. NCBI nr
Match: XP_022994036.1 (purple acid phosphatase 3-like [Cucurbita maxima])

HSP 1 Score: 102.8 bits (255), Expect = 1.8e-18
Identity = 52/66 (78.79%), Postives = 56/66 (84.85%), Query Frame = 0

Query: 1  MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQS 60
          MDAAAS R V LLL +VIA SGV+FT AEL+RF HP KDDGSLSLLVVGDWGR GEYNQS
Sbjct: 1  MDAAASIRRVGLLLWVVIAFSGVIFTAAELQRFSHPPKDDGSLSLLVVGDWGRKGEYNQS 60

Query: 61 QVALQV 67
          QVA Q+
Sbjct: 61 QVAAQM 66

BLAST of CaUC01G007190 vs. NCBI nr
Match: KAG6579177.1 (Purple acid phosphatase 3, partial [Cucurbita argyrosperma subsp. sororia])

HSP 1 Score: 102.4 bits (254), Expect = 2.4e-18
Identity = 50/66 (75.76%), Postives = 56/66 (84.85%), Query Frame = 0

Query: 1  MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQS 60
          MDA ASNR V LLL ++IA SGV+FT AEL+RF HP KDDGS+SLLVVGDWGR GEYNQS
Sbjct: 1  MDADASNRRVGLLLWVIIAFSGVVFTAAELQRFSHPPKDDGSISLLVVGDWGRKGEYNQS 60

Query: 61 QVALQV 67
          QVA Q+
Sbjct: 61 QVAAQM 66

BLAST of CaUC01G007190 vs. ExPASy Swiss-Prot
Match: Q8VYZ2 (Purple acid phosphatase 8 OS=Arabidopsis thaliana OX=3702 GN=PAP8 PE=2 SV=1)

HSP 1 Score: 73.6 bits (179), Expect = 1.6e-12
Identity = 42/82 (51.22%), Postives = 52/82 (63.41%), Query Frame = 0

Query: 1  MDAAASNRPVRL---LLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEY 60
          MD+    +P++L   + CLVI LS    T AEL RF  P + DGSLS LVVGDWGR G Y
Sbjct: 1  MDSLRDVKPIKLIFSIFCLVIILSACNST-AELPRFVQPPEPDGSLSFLVVGDWGRRGSY 60

Query: 61 NQSQVALQVLSLSPTTNLCNLV 80
          NQSQVALQ+  +    N+  L+
Sbjct: 61 NQSQVALQMGKIGKDLNIDFLI 81

BLAST of CaUC01G007190 vs. ExPASy Swiss-Prot
Match: Q8H129 (Purple acid phosphatase 3 OS=Arabidopsis thaliana OX=3702 GN=PAP3 PE=2 SV=1)

HSP 1 Score: 65.5 bits (158), Expect = 4.2e-10
Identity = 36/67 (53.73%), Postives = 44/67 (65.67%), Query Frame = 0

Query: 3  AAASNRPVRLLLC---LVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQ 62
          A   ++PV L+     L+I  S    T AELRR   PSK DG++S LV+GDWGR G YNQ
Sbjct: 32 ATLKHKPVNLVFYVYNLIIIFSSHSST-AELRRLLQPSKTDGTVSFLVIGDWGRRGSYNQ 91

Query: 63 SQVALQV 67
          SQVALQ+
Sbjct: 92 SQVALQM 97

BLAST of CaUC01G007190 vs. ExPASy Swiss-Prot
Match: Q9SCX8 (Purple acid phosphatase 17 OS=Arabidopsis thaliana OX=3702 GN=PAP17 PE=2 SV=1)

HSP 1 Score: 62.0 bits (149), Expect = 4.7e-09
Identity = 32/66 (48.48%), Postives = 44/66 (66.67%), Query Frame = 0

Query: 1  MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQS 60
          M A AS   + LLLC+      V+ ++ EL+RF  P+K DGS+S +V+GDWGR G +NQS
Sbjct: 9  MSATAS---LSLLLCIFTTF--VVVSNGELQRFIEPAKSDGSVSFIVIGDWGRRGSFNQS 68

Query: 61 QVALQV 67
           VA Q+
Sbjct: 69 LVAYQM 69

BLAST of CaUC01G007190 vs. ExPASy Swiss-Prot
Match: Q8VYU7 (Purple acid phosphatase 4 OS=Arabidopsis thaliana OX=3702 GN=PAP4 PE=2 SV=1)

HSP 1 Score: 59.3 bits (142), Expect = 3.0e-08
Identity = 30/55 (54.55%), Postives = 38/55 (69.09%), Query Frame = 0

Query: 12 LLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQSQVALQV 67
          LL+C ++ LS     +AEL    H    DGS+S LV+GDWGR+G YNQSQVALQ+
Sbjct: 16 LLICFLL-LSLAPKLEAELATVQHAPNPDGSISFLVIGDWGRHGLYNQSQVALQM 69

BLAST of CaUC01G007190 vs. ExPASy Swiss-Prot
Match: Q8S341 (Purple acid phosphatase 7 OS=Arabidopsis thaliana OX=3702 GN=PAP7 PE=2 SV=1)

HSP 1 Score: 51.6 bits (122), Expect = 6.3e-06
Identity = 28/59 (47.46%), Postives = 37/59 (62.71%), Query Frame = 0

Query: 10 VRLLLCLVIALSGVLFTDAELRRFPHP--SKDDGSLSLLVVGDWGRNGEYNQSQVALQV 67
          V L+   +  ++G L   ++L R  HP   K DGSLS LV+GDWGR G +NQS VA Q+
Sbjct: 9  VILMFLSIFFINGAL---SKLERLKHPVKKKSDGSLSFLVIGDWGRKGGFNQSLVAHQM 64

BLAST of CaUC01G007190 vs. ExPASy TrEMBL
Match: A0A1S4E6U0 (Acid phosphatase OS=Cucumis melo OX=3656 GN=LOC103483030 PE=3 SV=1)

HSP 1 Score: 108.6 bits (270), Expect = 1.6e-20
Identity = 59/77 (76.62%), Postives = 64/77 (83.12%), Query Frame = 0

Query: 3  AAASNRPVRLL-LCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQSQ 62
          AAASN  VRLL LCL+IALSGVL T A+L RF HPSKDDGSLSLLV+GDWGRNG+YNQS+
Sbjct: 2  AAASNHIVRLLILCLLIALSGVLLTRADLPRFAHPSKDDGSLSLLVLGDWGRNGDYNQSE 61

Query: 63 VALQVLSLSPTTNLCNL 79
          VALQVL LS T  L  L
Sbjct: 62 VALQVLPLSYTPPLFTL 78

BLAST of CaUC01G007190 vs. ExPASy TrEMBL
Match: A0A6J1FP06 (Purple acid phosphatase OS=Cucurbita moschata OX=3662 GN=LOC111445616 PE=3 SV=1)

HSP 1 Score: 103.2 bits (256), Expect = 6.8e-19
Identity = 51/66 (77.27%), Postives = 56/66 (84.85%), Query Frame = 0

Query: 1  MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQS 60
          MDA ASNR V LLL ++IA SGV+FT AEL+RF HP KDDGSLSLLVVGDWGR GEYNQS
Sbjct: 1  MDADASNRRVGLLLWVIIAFSGVVFTAAELQRFSHPPKDDGSLSLLVVGDWGRKGEYNQS 60

Query: 61 QVALQV 67
          QVA Q+
Sbjct: 61 QVAAQM 66

BLAST of CaUC01G007190 vs. ExPASy TrEMBL
Match: A0A6J1JY06 (Purple acid phosphatase OS=Cucurbita maxima OX=3661 GN=LOC111489845 PE=3 SV=1)

HSP 1 Score: 102.8 bits (255), Expect = 8.8e-19
Identity = 52/66 (78.79%), Postives = 56/66 (84.85%), Query Frame = 0

Query: 1  MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQS 60
          MDAAAS R V LLL +VIA SGV+FT AEL+RF HP KDDGSLSLLVVGDWGR GEYNQS
Sbjct: 1  MDAAASIRRVGLLLWVVIAFSGVIFTAAELQRFSHPPKDDGSLSLLVVGDWGRKGEYNQS 60

Query: 61 QVALQV 67
          QVA Q+
Sbjct: 61 QVAAQM 66

BLAST of CaUC01G007190 vs. ExPASy TrEMBL
Match: A0A5A7TSB4 (Purple acid phosphatase OS=Cucumis melo var. makuwa OX=1194695 GN=E5676_scaffold857G00100 PE=3 SV=1)

HSP 1 Score: 100.5 bits (249), Expect = 4.4e-18
Identity = 51/65 (78.46%), Postives = 57/65 (87.69%), Query Frame = 0

Query: 3  AAASNRPVRLL-LCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQSQ 62
          A ASN  VRLL LCL+IALSGVL T A+L RF HPSKDDGSLSLLV+GDWGRNG+YNQS+
Sbjct: 2  APASNHIVRLLILCLLIALSGVLLTRADLPRFAHPSKDDGSLSLLVLGDWGRNGDYNQSE 61

Query: 63 VALQV 67
          VALQ+
Sbjct: 62 VALQM 66

BLAST of CaUC01G007190 vs. ExPASy TrEMBL
Match: A0A0A0KP97 (Purple acid phosphatase OS=Cucumis sativus OX=3659 GN=Csa_5G548110 PE=3 SV=1)

HSP 1 Score: 99.0 bits (245), Expect = 1.3e-17
Identity = 49/65 (75.38%), Postives = 56/65 (86.15%), Query Frame = 0

Query: 3  AAASNRPVRL-LLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQSQ 62
          AAASN  V L +LCL+IALSG+L T AEL RF HPSKDDGSLSLLV+GDWGRNG+YNQS+
Sbjct: 5  AAASNHRVALPILCLLIALSGILLTRAELPRFAHPSKDDGSLSLLVLGDWGRNGDYNQSE 64

Query: 63 VALQV 67
          VA Q+
Sbjct: 65 VAFQM 69

BLAST of CaUC01G007190 vs. TAIR 10
Match: AT2G01890.1 (purple acid phosphatase 8 )

HSP 1 Score: 73.6 bits (179), Expect = 1.1e-13
Identity = 42/82 (51.22%), Postives = 52/82 (63.41%), Query Frame = 0

Query: 1  MDAAASNRPVRL---LLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEY 60
          MD+    +P++L   + CLVI LS    T AEL RF  P + DGSLS LVVGDWGR G Y
Sbjct: 1  MDSLRDVKPIKLIFSIFCLVIILSACNST-AELPRFVQPPEPDGSLSFLVVGDWGRRGSY 60

Query: 61 NQSQVALQVLSLSPTTNLCNLV 80
          NQSQVALQ+  +    N+  L+
Sbjct: 61 NQSQVALQMGKIGKDLNIDFLI 81

BLAST of CaUC01G007190 vs. TAIR 10
Match: AT2G01890.2 (purple acid phosphatase 8 )

HSP 1 Score: 73.6 bits (179), Expect = 1.1e-13
Identity = 42/82 (51.22%), Postives = 52/82 (63.41%), Query Frame = 0

Query: 1  MDAAASNRPVRL---LLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEY 60
          MD+    +P++L   + CLVI LS    T AEL RF  P + DGSLS LVVGDWGR G Y
Sbjct: 1  MDSLRDVKPIKLIFSIFCLVIILSACNST-AELPRFVQPPEPDGSLSFLVVGDWGRRGSY 60

Query: 61 NQSQVALQVLSLSPTTNLCNLV 80
          NQSQVALQ+  +    N+  L+
Sbjct: 61 NQSQVALQMGKIGKDLNIDFLI 81

BLAST of CaUC01G007190 vs. TAIR 10
Match: AT1G14700.1 (purple acid phosphatase 3 )

HSP 1 Score: 65.5 bits (158), Expect = 3.0e-11
Identity = 36/67 (53.73%), Postives = 44/67 (65.67%), Query Frame = 0

Query: 3  AAASNRPVRLLLC---LVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQ 62
          A   ++PV L+     L+I  S    T AELRR   PSK DG++S LV+GDWGR G YNQ
Sbjct: 32 ATLKHKPVNLVFYVYNLIIIFSSHSST-AELRRLLQPSKTDGTVSFLVIGDWGRRGSYNQ 91

Query: 63 SQVALQV 67
          SQVALQ+
Sbjct: 92 SQVALQM 97

BLAST of CaUC01G007190 vs. TAIR 10
Match: AT1G14700.2 (purple acid phosphatase 3 )

HSP 1 Score: 65.5 bits (158), Expect = 3.0e-11
Identity = 36/67 (53.73%), Postives = 44/67 (65.67%), Query Frame = 0

Query: 3  AAASNRPVRLLLC---LVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQ 62
          A   ++PV L+     L+I  S    T AELRR   PSK DG++S LV+GDWGR G YNQ
Sbjct: 32 ATLKHKPVNLVFYVYNLIIIFSSHSST-AELRRLLQPSKTDGTVSFLVIGDWGRRGSYNQ 91

Query: 63 SQVALQV 67
          SQVALQ+
Sbjct: 92 SQVALQM 97

BLAST of CaUC01G007190 vs. TAIR 10
Match: AT3G17790.1 (purple acid phosphatase 17 )

HSP 1 Score: 62.0 bits (149), Expect = 3.3e-10
Identity = 32/66 (48.48%), Postives = 44/66 (66.67%), Query Frame = 0

Query: 1  MDAAASNRPVRLLLCLVIALSGVLFTDAELRRFPHPSKDDGSLSLLVVGDWGRNGEYNQS 60
          M A AS   + LLLC+      V+ ++ EL+RF  P+K DGS+S +V+GDWGR G +NQS
Sbjct: 9  MSATAS---LSLLLCIFTTF--VVVSNGELQRFIEPAKSDGSVSFIVIGDWGRRGSFNQS 68

Query: 61 QVALQV 67
           VA Q+
Sbjct: 69 LVAYQM 69

The following BLAST results are available for this feature:
Match NameE-valueIdentityDescription
XP_016903715.13.3e-2076.62PREDICTED: purple acid phosphatase 4-like [Cucumis melo][more]
XP_022939885.11.4e-1877.27purple acid phosphatase 3-like [Cucurbita moschata][more]
XP_023550610.11.4e-1877.27purple acid phosphatase 17-like [Cucurbita pepo subsp. pepo][more]
XP_022994036.11.8e-1878.79purple acid phosphatase 3-like [Cucurbita maxima][more]
KAG6579177.12.4e-1875.76Purple acid phosphatase 3, partial [Cucurbita argyrosperma subsp. sororia][more]
Match NameE-valueIdentityDescription
Q8VYZ21.6e-1251.22Purple acid phosphatase 8 OS=Arabidopsis thaliana OX=3702 GN=PAP8 PE=2 SV=1[more]
Q8H1294.2e-1053.73Purple acid phosphatase 3 OS=Arabidopsis thaliana OX=3702 GN=PAP3 PE=2 SV=1[more]
Q9SCX84.7e-0948.48Purple acid phosphatase 17 OS=Arabidopsis thaliana OX=3702 GN=PAP17 PE=2 SV=1[more]
Q8VYU73.0e-0854.55Purple acid phosphatase 4 OS=Arabidopsis thaliana OX=3702 GN=PAP4 PE=2 SV=1[more]
Q8S3416.3e-0647.46Purple acid phosphatase 7 OS=Arabidopsis thaliana OX=3702 GN=PAP7 PE=2 SV=1[more]
Match NameE-valueIdentityDescription
A0A1S4E6U01.6e-2076.62Acid phosphatase OS=Cucumis melo OX=3656 GN=LOC103483030 PE=3 SV=1[more]
A0A6J1FP066.8e-1977.27Purple acid phosphatase OS=Cucurbita moschata OX=3662 GN=LOC111445616 PE=3 SV=1[more]
A0A6J1JY068.8e-1978.79Purple acid phosphatase OS=Cucurbita maxima OX=3661 GN=LOC111489845 PE=3 SV=1[more]
A0A5A7TSB44.4e-1878.46Purple acid phosphatase OS=Cucumis melo var. makuwa OX=1194695 GN=E5676_scaffold... [more]
A0A0A0KP971.3e-1775.38Purple acid phosphatase OS=Cucumis sativus OX=3659 GN=Csa_5G548110 PE=3 SV=1[more]
Match NameE-valueIdentityDescription
AT2G01890.11.1e-1351.22purple acid phosphatase 8 [more]
AT2G01890.21.1e-1351.22purple acid phosphatase 8 [more]
AT1G14700.13.0e-1153.73purple acid phosphatase 3 [more]
AT1G14700.23.0e-1153.73purple acid phosphatase 3 [more]
AT3G17790.13.3e-1048.48purple acid phosphatase 17 [more]
InterPro
Analysis Name: InterPro Annotations of Watermelon (USVL246-FR2) v1
Date Performed: 2022-01-31
IPR TermIPR DescriptionSourceSource TermSource DescriptionAlignment
NoneNo IPR availablePANTHERPTHR10161:SF42PURPLE ACID PHOSPHATASEcoord: 4..66
NoneNo IPR availablePANTHERPTHR10161TARTRATE-RESISTANT ACID PHOSPHATASE TYPE 5coord: 4..66

Relationships

The following mRNA feature(s) are a part of this gene:

Feature NameUnique NameType
CaUC01G007190.1CaUC01G007190.1mRNA


GO Annotation
GO Assignments
This gene is annotated with the following GO terms.
Category Term Accession Term Name
biological_process GO:0016311 dephosphorylation
cellular_component GO:0016021 integral component of membrane
molecular_function GO:0003993 acid phosphatase activity
molecular_function GO:0008199 ferric iron binding
molecular_function GO:0008198 ferrous iron binding