---
kind: "section"
citation: "21 C.F.R. § 173.170"
title: "21"
number: "173.170"
heading: "Aminoglycoside 3′-phosphotransferase II."
url: "https://uscodex.org/cfr/21/173.170"
---

# §173.170. Aminoglycoside 3′-phosphotransferase II.


The food additive aminoglycoside 3′-phosphotransferase II may be safely used in the development of genetically modified cotton, oilseed rape, and tomatoes in accordance with the following prescribed conditions:

- (a) **The food additive is the enzyme aminoglycoside 3′-phosphotransferase II (CAS Reg.** No. 58943-39-8) which catalyzes the phosphorylation of certain aminoglycoside antibiotics, including kanamycin, neomycin, and gentamicin.
- (b) Aminoglycoside 3′-phosphotransferase II is encoded by the kan r gene originally isolated from transposon Tn5 of the bacterium Escherichia coli.
- (c) The level of the additive does not exceed the amount reasonably required for selection of plant cells carrying the kan r gene along with the genetic material of interest.

## Notes

### Amendments

[59 FR 26711, May 23, 1994]

### Authority

Authority: 21 U.S.C. 321, 342, 348.

### Source

Source: 42 FR 14526, Mar. 15, 1977, unless otherwise noted.

### Amendments

[59 FR 26711, May 23, 1994]