Part:BBa_K2740015

CR1 nifK

CR1 nifK encodes the subunit beta (NifK) of the molybdenum-iron protein. Together with NifD, they form a α2β2 heterotetramer.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 856
  
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI.rc site found at 1106
  Illegal SapI.rc site found at 1489
  

Parameter of Protein

Number of amino acids: 509

Molecular weight: 56395.40

Theoretical pI: 5.74

Amino acid composition:
Ala (A)  48    9.4%
Arg (R)  26    5.1%
Asn (N)  16   3.1%
Asp (D)  27   5.3%
Cys (C)   9    1.8%
Gln (Q)  19    3.7%
Glu (E)  35    6.9%
Gly (G)  40    7.9%
His (H)  17    3.3%
Ile (I)   23     4.5%
Leu (L)  51  10.0%
Lys (K)  23    4.5%
Met (M)  19   3.7%
Phe (F)  24    4.7%
Pro (P)  26     5.1%
Ser (S)  29     5.7%
Thr (T)  28    5.5%
Trp (W)  2     0.4%
Tyr (Y)  19    3.7%
Val (V)  28    5.5%
Pyl (O)   0     0.0%
Sec (U)   0    0.0%

 (B)   0         0.0%
(Z)   0   0.0%
(X)   0         0.0%

 

Total number of negatively charged residues (Asp + Glu): 62
Total number of positively charged residues (Arg + Lys): 49

Atomic composition:

Carbon      C          2506
Hydrogen    H         3909
Nitrogen    N            681
Oxygen      O          745
Sulfur      S              28

Formula: C2506H3909N681O745S28
Total number of atoms: 7869

Extinction coefficients:

Extinction coefficients are in units of  M-1 cm-1, at 280 nm measured in water.

Ext. coefficient    39810
Abs 0.1% (=1 g/l)   0.706, assuming all pairs of Cys residues form cystines

 

Ext. coefficient    39310
Abs 0.1% (=1 g/l)   0.697, assuming all Cys residues are reduced

Estimated half-life:

The N-terminal of the sequence considered is M (Met).

The estimated half-life is: 30 hours (mammalian reticulocytes, in vitro).
>20 hours (yeast, in vivo).
>10 hours (Escherichia coli, in vivo).

 

Instability index:

The instability index (II) is computed to be 43.04
This classifies the protein as unstable.

 

Aliphatic index: 82.08

Grand average of hydropathicity (GRAVY): -0.197

Design Notes

Nitrogenase is a complex enzyme system consisting of nine protein components. Additionally, to maintain stoichiometry of these protein components is an essential requirement for nitrogenase biosynthesis and activity. However, there is only one copy of each structure gene present in the nif gene cluster. Therefore, cloning each of these nif genes and setting as independent part can facilitate the regulation of balancing expression ratios from the transcription and/or translation level(s) when they are heterogeneously expressed in non-diazotrophic hosts.