Table 1 Kinetic parameters for primer synthesis.

From: A primase subunit essential for efficient primer synthesis by an archaeal eukaryotic-type primase

Primase

kcat (min−1)

K m (μM)

kcat/Km (μM−1 min−1)

rNTP

 PriSL

ND*

ND*

14.3 × 10−4†

 PriSX

0.66±0.13‡

14.1±3.4

0.047

 PriSLX

1.31±0.09

3.2±0.75

0.409

dNTP

 PriSL

ND*

ND*

0.77 × 10−4†

 PriSX

ND§

8.75±0.6

ND§

 PriSLX

1.01±0.07

5.42±1.1

0.186

  1. dNTP, deoxynucleoside triphosphate; rNTP, ribonucleoside triphosphate; ND, not determined.
  2. *These parameters were not determined (ND) because the velocity of reaction increased linearly with an increasing substrate concentration under the assay conditions.
  3. †The kcat/Km values for PriSL are calculated based on the equation: v/[E]0=kcat[dNTP]/{Km+[dNTP]}=(kcat/Km) [dNTP] when Km is much larger than [dNTP].
  4. ‡s.e.m., n=3.
  5. §These parameters were not determined because of the interference of substrate inhibition (Ki: 244.8±8.6 μM).
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